Comprehensive Component Monitor - Engine

Engine Temperature Sensor Inputs 

Analog inputs such as Intake Air Temperature (P0112, P0113), Engine Coolant Temperature (P0117, P0118), Cylinder Head Temperature (P1289. P1290), Mass Air Flow (P0102, P0103) and Throttle Position (P0122, P0123, P1120), Fuel Temperature (P0182, P0183), Engine Oil Temperature (P0197, P0198), Fuel Rail Pressure (P0192, P0193) are checked for opens, shorts, or rationality by monitoring the analog -to-digital (A/D) input voltage.

DTCs	P0117 (low input), P0118 (high input)
Monitor execution	continuous
Monitor Sequence	None
Sensors OK	not applicable
Monitoring Duration	5 seconds to register a malfunction

Voltage < 0.244 volts or voltage > 4.96 volts

The ECT rationality test checks to make sure that ECT is not stuck in a range that causes other OBD to be disabled. If after a long (6 hour) soak, ECT is very high (> 230 °F) and is also much higher than IAT at start, it is assumed that ECT is stuck high. If after a long (6 hour) soak, ECT is stuck midrange between 175 °F (typical thermostat monitor threshold temperature) and 230 °F, it is assumed that ECT is stuck mid range.

DTCs	P0116 (ECT stuck high or midrange)
Monitor Execution	Once per driving cycle
Monitor Sequence	None
Sensors OK	ECT, CHT, IAT
Monitoring Duration for stuck high	On first valid sample after key on (engine does not have to start)
Monitoring Duration for stuck midrange	5 seconds to register a malfunction

Entry Condition	Minimum	Maximum
Engine-off time (soak time)	360 min
Difference between ECT and IAT (stuck high only)		50 deg
Engine Coolant Temperature for stuck high condition	230 °F
Engine Coolant Temperature for stuck midrange condition	175 °F	230 °F

ECT stuck high after first valid sample OR ECT stuck midrange for > 5 seconds

Currently, vehicles use either an ECT sensor or CHT sensor, not both. The CHT sensor measures cylinder head metal temperature as opposed to engine coolant temperature. At lower temperatures, CHT temperature is equivalent to ECT temperature. At higher temperatures, ECT reaches a maximum temperature (dictated by coolant composition and pressure) whereas CHT continues to indicate cylinder head metal temperature. If there is a loss of coolant or air in the cooling system, the CHT sensor will still provides an accurate measure of cylinder head metal temperature. If a vehicle uses a CHT sensor, the PCM software calculates both CHT and ECT values for use by the PCM control and OBD systems.

DTCs	P1289 (high input), P1290 (low input), P1299 (fail-safe cooling activated)
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK	Not applicable
Monitoring Duration	5 seconds to register a malfunction

Voltage < 0.244 volts or voltage > 4.96 volts For P1299, MIL illuminates immediately if CHT > 270°. Fuel shut-off is activated to reduce engine and coolant temperature

Beginning in the 2013 MY, an Exhaust Metal Temperature (EMT) sensor has been added to the 2.0L GTDI engine in some vehicles along with an ECT sensor. This EMT sensor is located in the cylinder head near the exhaust port. The signal correlates well to ECT during normal operating conditions with a properly filled and sealed coolant system. However, if the engine coolant system was damaged and coolant was low or lost, the EMT sensor will still sense the actual exhaust metal temperature while the ECT could be sitting in air instead of coolant (reading a much lower temperature). This sensor is used strictly for engine component protection via the PCM's "fail-safe" cooling algorithm with diagnostics for open and short circuit faults (P1289, P1290) along with the "fail-safe" cooling fault (P1299). This EMT sensor is actually a CHT sensor that only uses the high range resistor network, hence it uses the CHT "Hot End" transfer function shown below.

DTCs	P1289 (high input), P1290 (low input), P1299 (fail-safe cooling activated)
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK	Not Applicable
Monitoring Duration	5 seconds to register a malfunction

Voltage < 0.244 volts or voltage > 4.96 volts For P1299, MIL illuminates immediately if CHT > 270°. Fuel shut-off is activated to reduce engine and coolant temperature

DTCs	P0112 (low input), P0113 (high input)
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK	Not Applicable
Monitoring Duration	5 seconds to register a malfunction

Voltage < 0.244 volts or voltage > 4.96 volts

DTCs	P0197 (low input), P0198 (high input)
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK	Not Applicable
Monitoring Duration	5 seconds to register malfunction

Voltage < 0.20 volts or voltage > 4.96 volts

Volts	A/D counts in PCM	Temperature, degrees F
4.89	1001	-40
4.86	994	-31
4.81	983	-22
4.74	970	-13
4.66	954	-4
4.56	934	5
4.45	910	14
4.30	880	23
4.14	846	32
3.95	807	41
3.73	764	50
3.50	717	59
3.26	666	68
3.00	614	77
2.74	561	86
2.48	508	95
2.23	456	104
1.99	407	113
1.77	361	122
1.56	319	131
1.37	280	140
1.20	246	149
1.05	215	158
0.92	188	167
0.80	165	176
0.70	144	185
0.61	126	194
0.54	110	203
0.47	96	212
0.41	85	221
0.36	74	230
0.32	65	239
0.28	57	248
0.25	51	257
0.22	45	266
0.19	40	275
0.17	35	284
0.15	31	293
0.14	28	302

Volts	A/D counts in PCM	Temperature, degrees F
4.899	1002	-40
4.861	995	-31
4.812	985	-22
4.75	972	-14
4.671	956	-4
4.572	936	4
4.452	911	14
4.309	882	22
4.14	847	32
3.95	808	40
3.737	765	48
3.508	717	58
3.26	666	68
3.00	614	77
2.738	560	87
2.478	507	96
2.226	455	105
1.985	406	114
1.759	360	122
1.551	317	132
1.362	279	141
1.193	244	149
1.043	213	159
0.91	186	168
0.794	162	176
0.693	142	186
0.604	124	194
0.528	108	203
0.462	95	204

Volts	A/D counts in PCM	Temperature, degrees F
4.235	866	168
4.119	843	168
3.993	817	176
3.858	789	185
3.714	760	194
3.563	729	203
3.408	697	212
3.244	664	221
3.076	629	230
2.908	595	239
2.740	561	248
2.575	527	257
2.411	493	266
2.252	461	275
2.099	430	284
1.953	400	294
1.813	371	303
1.680	344	312
1.556	318	320
1.439	294	329
1.329	272	338
1.228	251	347
1.133	232	356
1.046	214	366
0.965	197	375
0.891	182	383
0.822	168	392
0.760	155	401
0.701	144	408
0.648	133	415
0.599	123	422
0.555	113	428
0.513	105	433
0.476	97	438
0.441	90	442
0.409	84	447
0.380	78	450
0.353	72	454
0.328	67	457
0.306	63	460
0.285	58	463
0.265	54	465
0.248	51	468
0.231	47	470
0.216	44	472
0.202	41	474
0.190	39	475
0.178	36	477
0.167	34	478
0.156	32	480

IAT Rationality Test 

The IAT rationality test determines if the IAT sensor is producing an erroneous temperature indication within the normal range of IAT sensor input.

The IAT sensor rationality test is run only once per power-up. The IAT sensor input is compared to the CHT sensor input (ECT sensor input on some applications) at key-on after a long (6 hour) soak. If the IAT sensor input and the CHT (ECT) sensor input agree within a tolerance (+/- 30 deg F), no malfunction is indicated and the test is complete. If the IAT sensor input and the CHT (ECT) sensor input differ by more than the tolerance, the vehicle must be driven over 35 mph for 5 minutes to confirm the fault. This is intended to address noise factors like sun load that can cause the IAT sensor to indicate a much higher temperature than the CHT (ECT) sensor after a long soak. Driving the vehicle attempts to bring the IAT sensor reading within the test tolerance. If the IAT sensor input remains outside of the tolerance after the vehicle drive conditions have been met, the test indicates a malfunction and the test is complete.

In addition to the start-up rationality check, an IAT "Out of Range" check is also performed. The test continuously, checks to see if IAT is greater than the "IAT Out of Range High threshold", approximately 150 deg F. In order to prevent setting false DTC during extreme ambient or vehicle soak conditions, the same count up/count down timer used for the IAT startup rationality test is used to validate the fault. If IAT is greater than 150 deg F and vehicle speed is greater than ~ 40 mph for 250 seconds then set a P0111.

Either the IAT startup rationality test or the IAT Out of Range High test can set a P0111 DTC. The logic is designed so that either fault can trigger a "two-in-a-row" P0111 MIL, however, both faults must be OK before the P0111 DTC is cleared.

Block heater detection results in a no-call.

DTCs	P0111 (range/performance)
Monitor execution	Once per driving cycle, at start-up
Monitor Sequence	None
Sensors OK	ECT/CHT, IAT, VSS
Monitoring Duration	Immediate or up to 30 minutes to register a malfunction

Entry condition	Minimum	Maximum
Engine off (soak) time	6 hours
Battery Voltage	11.0 Volts
Time since engine start (if driving req'd)		30 min
Vehicle speed (if driving req'd)	40 mph
Time above minimum vehicle speed (if driving req'd)	5 min
IAT - ECT at start (block heater inferred)	-30 °F	-90 °F

IAT and ECT/CHT error at start-up > +/-30 deg F

DTCs	P0111 (Out of Range High)
Monitor execution	Continuous
Monitor Sequence	None
Sensors OK	ECT/CHT, IAT, VSS
Monitoring Duration	250 seconds to register a malfunction

Entry Condition	Minimum	Maximum
Engine off (soak) time	6 hours
Battery Voltage	11.0 Volts
Vehicle speed	40 mph
Time above minimum vehicle speed (if driving req'd)	5 min

IAT > 150 deg F

The IAT rationality test employs alternate statistical MIL illumination. This protocol allows up to 6 trips before MIL illumination based on the magnitude of the measured error. The greater the error the fewer number of trips before a DTC will be indicated. In the case of the IAT rationality test the measured error is the difference between the IAT input and the CHT (ECT) input.

The error space is divided into bands. Each band represents a range of error. There are two bands for each of; 5 trips to pending DTC, 4 trips to pending DTC, 3 trips to pending DTC, 2 trips to pending DTC and 1 trip to pending DTC. There are two bands for each because there is one band for positive error and one band for negative error of the same magnitude range.

Counters are maintained that keep track of how many trips a malfunction has occurred within each band. When a sufficient number of trips with a malfunction has been achieved in any band, a P0111 DTC will be set.

If an IAT error, trip to trip, remains just above the IAT-out-of-range error threshold, it will take 6 trips to illuminate the MIL. If the IAT-out-of-range error, trip to trip, is much larger (80 deg F), the MIL will illuminate in the standard 2 trips.

Fuel Rail Pressure Sensor 

DTCs	P0192 (low input), P0193 (high input)
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK	Not Applicable
Monitoring Duration	8 seconds to register a malfunction

Voltage < 0.049 volts or voltage > 4.88 volts

FRP volts = [ Vref * (4 * Fuel Pressure / 70) + 0.50 ] / 5.00
Volts	A/D counts in PCM	Pressure, psi
4.85	993	76.125
4.50	922	70
1.00	820	61.25
3.50	717	52.5
3.00	614	43.75
2.50	512	35
2.00	410	26.25
1.50	307	17.5
1.00	205	8.75
0.50	102	0
0.15	31	-6.125

The FRP range/performance test checks to make sure that fuel rail pressure can be properly controlled by the electronic returnless fuel system. The FPS sensor is also checked for in-range failures that can be caused by loss of Vref to the sensor. Note that the FRP is referenced to manifold vacuum (via a hose) while the fuel rail pressure sensor is not referenced to manifold vacuum. It uses gage pressure. As a result, a mechanical gage in the fuel rail will display a different pressure than the FPR PID on a scan tool. The scan tool PID will read higher because of manifold vacuum.

DTCs	P0191 (FRP range/performance), P1090 (stuck in range)
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK	FRP
Monitoring Duration	8 seconds to register a malfunction

Entry Condition	Minimum	Maximum
Demand pressure reasonable	35 psig	60 psig
Fuel Level	15%

Fuel pressure error (demand - actual pressure) > 20 psig

Entry Condition	Minimum	Maximum
FRP sensor input	0 psig	46 psig
FRP input not moving		1 psig/sec

Fuel pressure error (demand - actual pressure) > 5 psig

Mass Air Flow Sensor 

The analog MAF sensor uses a hot wire sensing element to measure the amount of air entering the engine. Air passing over the hot wire causes it to cool. This hot wire is maintained at 200°C (392°F) above the ambient temperature as measured by a constant cold wire. The current required to maintain the temperature of the hot wire is proportional to the mass air flow. The MAF sensor then outputs an analog voltage proportional to the intake air mass.

The MAF sensor is located between the air cleaner and the throttle body or inside the air cleaner assembly. Most MAF sensors have integrated bypass technology with an integrated IAT sensor. The hot wire electronic sensing element must be replaced as an assembly. Replacing only the element may change the air flow calibration.

For the 2011 MY, some vehicles will use a digital MAF sensor, which outputs a frequency proportional to the intake air mass.

DTCs	Analog Sensor: P0102 (low input), P0103 (high input) Digital Sensor: P0100 (broken element), P0102 (low input), P0103 (high input)
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK	Not Applicable
Monitoring Duration	5 seconds to register a malfunction

Analog Sensor: Voltage < 0.244 volts and engine running or voltage > 4.785 volts engine rpm < 4, 000 rpm Digital Sensor: With engine running, frequency < 750 Hz or frequency = 0

Manifold Absolute Pressure Sensor 

The MAP (Manifold Absolute Pressure) sensor provides a voltage proportional to the absolute pressure in the intake manifold using a piezo-resistive silicon sensing element. The pressure sensor is typically mounted into a port on the engine intake manifold.

In the 2014 MY, some vehicles will be using MAP sensor in place of a MAF sensor for airflow measurement. The MAP sensor is checked for opens, shorts, or out-of-range values by monitoring the analog-to-digital (A/D) input voltage.

Vout=(Vref / 5) * 0.0409523809* Pressure (in kPa) + -0.1095238095)
Volts	Pressure, kPa	Pressure, Inches Hg
0.30	10.0	2.59
0.38	12.0	3.54
1.00	27.0	7.97
2.35	60.0	17.72
3.37	85.0	25.10
4.48	112.0	33.07
4.60	115.0	33.96

DTCs	P0107 (low voltage), P0108 (high voltage)
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK	Not Applicable
Monitoring Duration	5 seconds to register malfunction

Battery voltage > 11.0 volts

Voltage < 0.19 volts or voltage > 4.88 volts

MAF/MAP - TP Rationality Test 

The MAF or MAP and TP sensors are cross-checked to determine whether the sensor readings are rational and appropriate for the current operating conditions. (P0068) The test uses the calculated load value (LOAD) which can be computed from MAF for a mass air flow system or from MAP for a speed density system.

DTCs	P0068 - MAP / MAF - Throttle Position Correlation
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK
Monitoring Duration	3 seconds within test entry conditions

Entry Condition	Minimum	Maximum
Engine RPM	550 rpm	min of 5000 rpm
Engine Coolant Temp	150 °F

Load > 60% and TP < 2.4 volts or Load < 30% and TP > 2.4 volts

Miscellaneous CPU Tests 

Loss of Keep Alive Memory (KAM) power (a separate wire feeding the PCM) results is a P1633 DTC and immediate MIL illumination. (Used for those modules that use KAM.)

Vehicles that require tire/axle information and VIN to be programmed into the PCM Vehicle ID block (VID) will store a P1639 if the VID block is not programmed or corrupted.

P0602  - Powertrain Control Module Programming Error indicates that the Vehicle ID block check sum test failed.

P0603  - Powertrain Control Module Keep Alive Memory (KAM) Error indicates the Keep Alive Memory check sum test failed. (Used for those modules that use KAM.)

P0604  - Powertrain Control Module Random Access Memory (RAM) Error indicates the Random Access Memory read/write test failed.

P0605  - Powertrain Control Module Read Only Memory (ROM) Error indicates a Read Only Memory check sum test failed.

P0607  - Powertrain Control Module Performance indicates incorrect CPU instruction set operation, or excessive CPU resets.

P0610  - Powertrain Control Module indicates that one or more of the VID Block fields were configured incorrectly.

P068A  - ECM/PCM Power Relay De-energized - Too Early. This fault indicates that NVRAM write did not complete successfully after the ignition key was turned off, prior to PCM shutdown.

P06B8  - Internal Control Module Non-Volatile Random Access Memory (NVRAM) Error indicates Permanent DTC check sum test failed

U0101  - Lost Communication with Transmission Control Module (for vehicles with standalone TCM)

P1934  - Lost Vehicle Speed Signal from ABS Module

Engine Off Timer Monitor 

The engine off timer is either implemented in a hardware circuit in the PCM or is obtained via a CAN message from the Body Control Module.

If the timer is implemented in the PCM, the following applies:

There are two parts to the test. The first part determines that the timer is incrementing during engine off. The test compares ECT prior to shutdown to ECT at key-on. The ECT has cooled down more than 30 deg F and the engine had warmed up to at least 160 deg F prior to shutdown, then an engine off soak has occurred. If the engine off timer indicates a value less than 30 sec, then the engine of timer is not functioning and a P2610 DTC is set.

The second part looks at the accuracy of the engine off timer itself. The timer in the satellite chip is allowed to count up for 5 minutes with the engine running and compared to a different clock in the main microprocessor. If the two timers differ by more than 15 sec (5%), a P2610 DTC is set.

If engine off time is obtained from the BCM, the following applies. There are multiple parts to the test:

The PCM expects to get a CAN message with the engine off time from BCM shortly after start. If the engine off time is not available because of a battery disconnect, the CAN message is set to FFFFh and a U0422 is set (Invalid Data Received from BCM).

If the CAN message with engine off time is not available, a P2610 DTC is set and a U0140 is set (Lost Communication with BCM).

As above, the next part determines that the timer is incrementing during engine off. The test compares ECT prior to shutdown to ECT at key-on. The ECT has cooled down more than 30 deg F and the engine had warmed up to at least 160 deg F prior to shutdown, then an engine off soak has occurred. If the engine off timer indicates a value less than 30 sec, then the engine of timer is not functioning and a P2610 DTC is set.

The last part looks at the accuracy of the engine off timer itself. The timer in the BCM (Global Real Time) is sampled for 5 minutes with the engine running and compared to the clock in the main microprocessor. If the two timers differ by more than 15 sec (5%), a P2610 DTC is set.

DTCs	P2610
Monitor Execution	Continuous within entry conditions
Monitor Sequence	None
Monitoring Duration	Immediately on startup or after 5 min

Engine off time < 30 seconds after inferred soak Engine off timer accuracy off by > 15 sec. Engine off time CAN message missing at startup

DTCs	P0642 - Sensor Reference Voltage "A" Circuit Low P0643 - Sensor Reference Voltage "A" Circuit High
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK	Not Applicable
Monitoring Duration	5 sec to register a malfunction

Entry Condition	Minimum	Maximum
Ignition "ON"	NA	NA

P0642  Short to ground (signal voltage): < 4.75 V P0643  Short to battery plus (signal voltage): > 5.25 V

DTCs	P06A6 - Sensor Reference Voltage "A" Circuit Range/Performance P06A7 - Sensor Reference Voltage "B" Circuit Range/Performance P06A8 - Sensor Reference Voltage "C" Circuit Range/Performance
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK	Not Applicable
Monitoring Duration	0.5 sec to register a malfunction

Entry Condition	Minimum	Maximum
Ignition "ON"	NA	NA

P0646, P0647, P06A8 (used for Bosch Tricore modules) Reference voltage: < 4.7 V or reference voltage: > 5.2 V

Central Vehicle Configuration 

On some applications, the Body Control Module (BCM) transmits VIN, Tire Circumference, Axle Ratio and Cruise Control Configuration (CCC) over the vehicle CAN network to the ECM/PCM as well as to other modules in the vehicle that use this information. Valid data received by the ECM/PCM s stored into NVRAM. This feature is known as Central Vehicle Configuration.

CAN messages with this data are sent every time the vehicle is started. If the CAN messages are not received after start, a U0140 (Lost Communication with BCM) DTC is set. Next, the data is checked to ensure that it is in a valid range. If the VIN, tire, axle or CCC are not in a valid range, a U0422 (Invalid Data received from BCM) DTC is set.

The system is designed to automatically accept valid VIN, tire, axle and CCC data if only the default data ($FF) is stored. If the default VIN, tire and axle are not replaced with valid data at the vehicle assembly plant or after service, a P0630 (VIN and/or tire/axle not programmed) DTC is set and the MIL is illuminated.

The flow charts below describe the process.

Ignition System Tests 

New floating point processors no longer use an EDIS chip for ignition signal processing. The crank and cam position signals are now directly processed by the PCM/ECM microprocessor using a special interface called a Time Processing Unit or TPU, or General Purpose Time Array (GPTA), depending on the PCM/ECM. The signals to fire the ignition coil drivers also come from the microprocessor.

Historically, Ford has used a 36-1 tooth wheel for crankshaft position (40-1 on a V-10). Many engines still use a 36- 1 wheel; however, some new engines are migrating to a 60-2 tooth wheel for crankshaft position. This was done to commonize ignition hardware and allow Ford to use some industry-standard PCM/ECM designs. 60-2 tooth crank wheels are being used on the 2011/2012 MY 2.0L GDI and GTDI engines, 1.6L GTDI engines and the 3.5L TIVCT GTDI engine.

Over the years, Ford ignition system have migrated away from Distributorless Ignition Systems (DIS) where a given coil pack fires two spark plugs at the same time (one spark plug fires during the compression stroke, the other spark plug fires during the exhaust stroke). All new engine now use Coil On Plug (COP) systems where there is an ignition coil and a coil driver for each spark plug, thus eliminating the need for secondary spark plug wires and improving reliability. Historically, Ford located the ignition coil drivers within the PCM/ECM, however, some new engines are migrating to coils where the driver is located on the coil itself. This eliminates the high current lines going from the PCM to the coils and again, commonizes ignition hardware to allow Ford to use some industry standard PCM/ECM designs.

The ignition system is checked by monitoring various ignition signals during normal vehicle operation:

CKP, the signal from the crankshaft 36-1-or 60-2 tooth wheel. The missing tooth is used to locate the cylinder pair associated with cylinder # 1 The microprocessor also generates the Profile Ignition Pickup (PIP) signal, a 50% duty cycle, square wave signal that has a rising edge at 10 deg BTDC for 36-1 systems and 12 deg BTDC for 60-2 systems.

Camshaft Position (CMP), a signal derived from the camshaft to identify the #1 cylinder

Coil primary current (driver in module ignition systems). The NOMI signal indicates that the primary side of the coil has achieved the nominal current required for proper firing of the spark plug. This signal is received as a digital signal from the coil drivers to the microprocessor. The coil drivers determine if the current flow to the ignition coil reaches the required current (typically 5.5 Amps for COP, 3.0 to 4.0 Amps for DIS) within a specified time period (typically > 200 microseconds for both COP and DIS).

Coil driver circuit current and/or voltage (driver on coil ignition systems). The PCM/ECM coil driver IC checks for out of range current and voltage levels at the coil driver output that would indicate an open or short circuit fault. The fault could be located anywhere in the coil driver circuit: PCM/ECM, wiring harness, coil connector, or the driver circuit on the ignition coil. (Note this does not include the primary side windings. Faults in the primary side windings must be detected by the Misfire Monitor for driver on coil ignition systems).

First, several relationships are checked on the CKP signal. The microprocessor looks for the proper number of teeth (35 or 39 or 58) after the missing tooth is recognized; time between teeth too low (< 30 rpm or > 9, 000 rpm); or the missing tooth was not where it was expected to be. If an error occurs, the microprocessor shuts off fuel and the ignition coils and attempts to re-synchronize itself. It takes on revolution to verify the missing tooth, and another revolution to verify cylinder #1 using the CMP input. Note that if a P0320 or P0322 DTC is set on a vehicle with Electronic Throttle Control, (ETC), the ETC software will also set a P2106.

If the proper ratio of CMP events to PIP events is not being maintained (for example, 1 CMP edge for every 8 PIP edges for an 8-cylinder engine), it indicates a missing or noisy CMP signal (P0340). On applications with Variable Cam Timing (VCT), the CMP wheel has five teeth to provide the VCT system with more accurate camshaft control. The microprocessor checks the CMP signal for an intermittent signal by looking for CMP edges where they would not be expected to be. If an intermittent is detected, the VCT system is disabled and a P0344 (CMP Intermittent Bank 1) or P0349 (CMP intermittent Bank 2) is set.

Finally, for driver in module ignition systems, the relationship between NOMI events and PIP events is evaluated. If there is not an NOMI signal for every PIP edge (commanded spark event), the PCM will look for a pattern of failed NOMI events to determine which ignition coil has failed.

DTCs	P0320 Ignition Engine Speed Input Circuit P0322 Ignition Engine Speed Input Circuit No Signal P0339 Crankshaft Position Sensor "A" Circuit Intermittent P0335 Crankshaft Position Sensor "A" Circuit
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK
Monitoring Duration	< 5 seconds

Entry Condition	Minimum	Maximum
Engine RPM for CKP	500 rpm

P0320 or P0339  : Incorrect number of teeth after the missing tooth is recognized, time between teeth too low (< 30 rpm or > 9, 000 rpm), missing tooth was not where it was expected to be. P0322 or P0335:  Camshaft indicates > 1 engine revolution while crankshaft signal missing

DTCs	P0340 - Intake Cam Position Circuit, Bank 1 P0344 - Intake Cam Position Circuit Intermittent, Bank 1 P0345 - Intake Cam Position Circuit, Bank 2 P0349 - Intake Cam Position Circuit Intermittent Bank 2 P0365 - Exhaust Cam Position Circuit, Bank 1 P0369 - Intake Cam Position Circuit Intermittent, Bank 1 P0390 - Exhaust Cam Position Circuit, Bank 2 P0394 - Exhaust Cam Position Circuit Intermittent Bank 2
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK
Monitoring Duration	< 5 seconds

Entry Condition	Minimum	Maximum
Engine RPM for CMP	200 rpm

Ratio of PIP events to CMP events: 4:1, 6:1, 8:1 or 10:1 based on engine cyl. Intermittent CMP signal - CMP signal in unexpected location

DTCs	P0351 - P0360 (Coil primary) P2300, P2303, P2306, P2309, P2312, P2315, P2318, P2321, P2324, P2327 (Coil driver short circuit low) P2301, P2304, P2307, P2310, P2313, P2316, P2319, P2322, P2325, P2328 (Coil driver short circuit high) P06D1 (Internal control module ignition coil control module performance)
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK
Monitoring Duration	< 1 seconds

Entry Condition	Minimum	Maximum
Engine RPM for Coil Primary	200 rpm	Min of 3200 rpm
Positive Engine Torque	Positive Torque
Battery Voltage	11 Volts	16 Volts

P035x (driver in module Ignition systems): Ratio of PIP events to IDM or NOMI events 1:1 P035x, P23xx (driver on coil Ignition systems): Coil driver circuit current and/or voltage out of range of open and short circuit limits. P06D1 (driver on coil Ignition systems): Missing communication from coil driver IC.

If an ignition coil primary circuit failure is detected for a single cylinder or coil pair, the fuel injector to that cylinder or cylinder pair will be shut off for 30 seconds to prevent catalyst damage. Up to two cylinders may be disabled at the same time on 6 and 8 cylinder engines and one cylinder is disabled on 4 cylinder engines. After 30 seconds, the injector is re-enabled. If an ignition coil primary circuit failure is again detected, (about 0.10 seconds), the fuel injector will be shut off again and the process will repeat until the fault is no longer present. Note that engine misfire can trigger the same type of fuel injector disablement.

Knock Sensor 

Due to the design of the knock sensor input circuitry, a short to battery, short to ground, or open circuit all result is a low knock signal voltage output. This output voltage is compared to a noise signal threshold (function of engine rpm and load) to determine knock sensor circuit high, circuit low or performance faults.

Some PCM/ECM modules use a driver circuit that will periodically and actively test the knock sensor lines for short circuit faults. In these modules, supplemental codes can be set for the short circuit condition.

Some PCM/ECM modules use a standalone Knock IC. In these modules, the knock signal processing chip SPI bus is checked for proper communication between the main processor and the chip used as the interface the knock sensor.

DTCs	P0325 - Knock Sensor 1 Circuit P0330 - Knock Sensor 2 Circuit P0327 - Knock Sensor 1 Circuit Low P0328 - Knock Sensor 1 Circuit High P0332 - Knock Sensor 2 Circuit Low P0333 - Knock Sensor 2 Circuit High P06B6 - Lost Comm with Knock IC Chip
Monitor Execution	Continuous within entry conditions
Monitor Sequence	None
Sensors OK	Not in failsafe cooling mode
Monitoring Duration	2.5 seconds

Entry Condition	Minimum	Maximum
Time since engine start (function of ECT)	60 to 20 sec
Engine Coolant Temperature	140 °F
Engine Load	35%
Engine Speed	1500 rpm	6000 rpm

P0325 & P0330  Knock signal too low (function of engine speed): < 30 to 150 A/D counts (out of 255) P0327, P0332  (used only for PCM/ECM with corresponding diagnostic circuit) Voltage level from active knock sensor circuit probe below limit P0328, P0333  (used only for PCM/ECM with corresponding diagnostic circuit) Voltage level from active knock sensor circuit probe above limit) P06B6  (used only for PCM/ECM with standalone Knock IC) Cylinder events with missing communication from Knock IC > 200

Engine Outputs 

The Idle Air Control (IAC) solenoid is checked electrically for open and shorts (P0511) and is functionally checked by monitoring the closed loop idle speed correction required to maintain the desired idle rpm. If the proper idle rpm cannot be maintained and the system has a high rpm (+200) or low rpm error (-100) greater than the malfunction threshold, an IAC malfunction is indicated. (P0507, P0506)

DTCs	P0511 (opens/shorts) P0507 (functional - overspeed) P0506 (functional - underspeed)
Monitor Execution	once per driving cycle
Monitor Sequence	None
Sensors OK
Monitoring Duration	15 seconds

Entry Condition	Minimum	Maximum
Engine Coolant Temp	150 °F
Time since engine start-up	30 Seconds
Closed loop fuel	Yes
Throttle Position (at idle, closed throttle, no dashpot)	Closed	Closed

For underspeed error: Actual rpm 100 rpm below target, closed-loop IAC correction > 1 lb/min For overspeed error: Actual rpm 200 rpm above target, closed-loop IAC correction <.2 lb/min

The PCM monitors the "smart" driver fault status bit that indicates either an open circuit, short to power or short to ground.

DTCs	P0201 through P0210 (opens/shorts)
Monitor Execution	Continuous within entry conditions
Monitor Sequence	None
Monitoring Duration	5 seconds

Entry Condition	Minimum	Maximum
Battery Voltage	11.0 volts

Electronic Returnless Fuel System 

Electronic Returnless Fuel Systems (ERFS) utilize a Fuel Pump Driver Module (FPDM) to control fuel pressure. The PCM uses a Fuel Rail Pressure Sensor (FRP) for feedback. The PCM outputs a duty cycle to the FPDM to maintain the desired fuel rail pressure. During normal operation, the PCM will output a FP duty cycle from 5% to 51%. The FPDM will run the fuel pump at twice this duty cycle, e.g. if the PCM outputs a 42% duty cycle, the FPDM will run the fuel pump at 84%. If the PCM outputs a 75% duty cycle, the FPDM will turn off the fuel pump.

The FPDM returns a duty cycled diagnostic signal back to the PCM on the Fuel Pump Monitor (FPM) circuit to indicate if there are any faults in the FPDM.

If the FPDM does not out any diagnostic signal, (0 or 100% duty cycle), the PCM sets a P1233 DTC. This DTC is set if the FPDM loses power. This can also occur if the Inertia Fuel Switch is tripped.

If the FPDM outputs a 25% duty cycle, it means that the fuel pump control duty cycle is out of range. This may occurs if the FPDM does not receive a valid control duty cycle signal from the PCM. The FPDM will default to 100% duty cycle on the fuel pump control output. The PCM sets a P1235 DTC.

If the FPDM outputs a 75% duty cycle, it means that the FPDM has detected an open or short on the fuel pump control circuit. The PCM sets a P1237 DTC.

If the FPDM outputs a 50% duty cycle, the FPDM is functioning normally.

DTCs	P1233 - FPDM disabled of offline P1235 - Fuel pump control out of range P1237 - Fuel pump secondary circuit
Monitor Execution	Continuous, voltage > 11.0 volts
Monitor Sequence	None
Monitoring Duration	3 seconds

Mechanical Returnless Fuel System (MRFS) - Single Speed 

An output signal from the PCM is used to control the electric fuel pump. The PCM grounds the FP circuit, which is connected to the coil of the fuel pump relay. This energizes the coil and closes the contacts of the relay, sending B+ through the FP PWR circuit to the electric fuel pump. When the ignition is turned on, the electric fuel pump runs for about 1 second and is turned off by the PCM if engine rotation is not detected.

The FPM circuit is spliced into the fuel pump power (FP PWR) circuit and is used by the PCM for diagnostic purposes. With the fuel pump on and the FPM circuit high, the PCM can verify the FP PWR circuit from the fuel pump relay to the FPM splice is complete. It can also verify the fuel pump relay contacts are closed and there is a B+ supply to the fuel pump relay.

Mechanical Returnless Fuel System (MRFS) - Dual Speed 

The FP signal is a duty cycle command sent from the PCM to the fuel pump control module. The fuel pump control module uses the FP command to operate the fuel pump at the speed requested by the PCM or to turn the fuel pump off. A valid duty cycle to command the fuel pump on, is in the range of 15-47%. The fuel pump control module doubles the received duty cycle and provides this voltage to the fuel pump as a percent of the battery voltage. When the ignition is turned on, the fuel pump runs for about 1 second and is requested off by the PCM if engine rotation is not detected.

FP Duty Cycle Command	PCM Status	Fuel Pump Control Module Actions
0-15%	Invalid off duty cycle	The fuel pump control module sends a 20% duty cycle signal on the fuel pump monitor (FPM) circuit. The fuel pump is off.
37%	Normal low speed operation.	The fuel pump control module operates the fuel pump at the speed requested. The fuel pump control module sends a 60% duty cycle signal on FPM circuit.
47%	Normal high speed operation.	The fuel pump control module operates the fuel pump at the speed requested. The fuel pump control module sends a 60% duty cycle signal on FPM circuit.
51-67%	Invalid on duty cycle.	The fuel pump control module sends a 20% duty cycle signal on the FPM circuit. The fuel pump is off.
67-83%	Valid off duty cycle	The fuel pump control module sends a 60% duty cycle signal on FPM circuit. The fuel pump is off.
83-100%	Invalid on duty cycle.	The fuel pump control module sends a 20% duty cycle signal on the FPM circuit. The fuel pump is off.

The fuel pump control module communicates diagnostic information to the PCM through the FPM circuit. This information is sent by the fuel pump control module as a duty cycle signal. The 4 duty cycle signals that may be sent are listed in the following table.

Duty Cycle	Comments
20%	This duty cycle indicates the fuel pump control module is receiving an invalid duty cycle from the PCM.
40%	For vehicles with event notification signal, this duty cycle indicates the fuel pump control module is receiving an invalid event notification signal from the RCM. For vehicles without event notification signal, this duty cycle indicates the fuel pump control module is functioning normally.
60%	For vehicles with event notification signal, this duty cycle indicates the fuel pump control module is functioning normally.
80%	This duty cycle indicates the fuel pump control module is detecting a concern with the secondary circuits.

DTCs	P025A - Fuel Pump Control (open/shorts) P025B - Invalid Fuel Pump Control Data (20% duty cycle from FPM) P0627 - Fuel Pump Secondary Circuit (80% duty cycle from PFM) U2010B - Fuel Pump Disabled Circuit (40% duty cycle from FPM) U0109 - Loss of Communication with Fuel Pump Module
Monitor Execution	once per driving cycle
Monitor Sequence	None
Sensors OK
Monitoring Duration	2 seconds

Entry Condition	Minimum	Maximum
Battery Voltage	11 volts

P025A FP output driver indicates fault P025B, P0627, U210B Fuel Pump Monitor duty cycle feedback of 20, 40 or 80% U0191 No Fuel Pump Monitor duty cycle feedback

There are several different styles of hardware used to control airflow within the engine air intake system. In general, the devices are defined based on whether they control in-cylinder motion (charge motion) or manifold dynamics (tuning).

Systems designed to control charge motion are defined to be Intake Manifold Runner Controls. IMRC systems generally have to modify spark when the systems are active because altering the charge motion affects the burn rate within the cylinder.

Systems designed to control intake manifold dynamics or tuning are defined to be Intake Manifold Tuning Valves. IMTV systems generally do not require any changes to spark or air/fuel ratio because these systems only alter the amount of airflow entering the engine.

Intake Manifold Runner Control Systems 

The Intake Manifold Runner Control (IMRC) consists of a remote mounted, electrically motorized actuator with an attaching cable for each housing on each bank. Some applications will use one cable for both banks. The cable or linkage attaches to the housing butterfly plate levers. (The Focus IMRC uses a motorized actuator mounted directly to a single housing without the use of a cable.)

The IMRC housing is an aluminum casting with two intake air passages for each cylinder. One passage is always open and the other is opened and closed with a butterfly valve plate. The housing uses a return spring to hold the butterfly valve plates closed. The motorized actuator houses an internal switch or switches, depending on the application, to provide feedback to the PCM indicating cable and butterfly valve plate position.

Below approximately 3000 rpm, the motorized actuator will not be energized. This will allow the cable to fully extend and the butterfly valve plates to remain closed. Above approximately 3000 rpm, the motorized actuator will be energized. The attaching cable will pull the butterfly valve plates into the open position. (Some vehicles will activate the IMRC near 1500 rpm.)

The Intake Manifold Swirl Control used on the 2.3L Ranger consists of a manifold mounted vacuum actuator and a PCM controlled electric solenoid. The linkage from the actuator attaches to the manifold butterfly plate lever. The IMSC actuator and manifold are composite/plastic with a single intake air passage for each cylinder. The passage has a butterfly valve plate that blocks 60% of the opening when actuated, leaving the top of the passage open to generate turbulence. The housing uses a return spring to hold the butterfly valve plates open. The vacuum actuator houses an internal monitor circuit to provide feedback to the PCM indicating butterfly valve plate position.

Below approximately 3000 rpm, the vacuum solenoid will be energized. This will allow manifold vacuum to be applied and the butterfly valve plates to remain closed. Above approximately 3000 rpm, the vacuum solenoid will be de-energized. This will allow vacuum to vent from the actuator and the butterfly valve plates to open.

DTCs	P2014 - IMRC input switch electrical check, Bank 1 P2008 - IMRC output electrical check P2004 - IMRC stuck open, electric operated P2004 - IMRC stuck open, vacuum operated, Bank 1 P2005 - IMRC stuck open, vacuum operated, Bank 2 P2006 - IMRC stuck closed, electric operated
Monitor Execution	Continuous, after ECT > 40 deg F
Monitor Sequence	None
Sensors OK
Monitoring Duration	5 seconds

IMRC plates do not match commanded position (functional) IMRC switches open/shorted (electrical)

Intake Manifold Tuning Valve Systems 

The intake manifold tuning valve (IMTV) is a motorized actuated unit mounted directly to the intake manifold. The IMTV actuator controls a shutter device attached to the actuator shaft. There is no monitor input to the PCM with this system to indicate shutter position.

The motorized IMTV unit will not be energized below approximately 2600 rpm or higher on some vehicles. The shutter will be in the closed position not allowing airflow blend to occur in the intake manifold. Above approximately 2600 rpm or higher, the motorized unit will be energized. The motorized unit will be commanded on by the PCM initially at a 100 percent duty cycle to move the shutter to the open position and then falling to approximately 50 percent to continue to hold the shutter open.

DTCs	P1549 or P0660 - IMTV output electrical check (does not illuminate MIL)
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK
Monitoring Duration	5 seconds

Engine Cooling System Outputs 

The engine cooling system may contain multiple control valves for improving fluid warm-up rates of both the engine and transmission. These valves are PCM controlled and primarily used for thermal control of engine metal and transmission fluid temperatures by diverting engine coolant to the appropriate component. These digital outputs include an engine coolant bypass valve (CBV), a heater core shut-off valve (HCSO), an active transmission heating valve (ATWU-H), and an active transmission cooling valve (ATWU-C).

The Coolant Bypass Valve is normally closed (de-energized) forcing all of the engine coolant through the radiator to provide maximum "cooling" of the engine and components when the thermostat is open. When opened, a portion of the engine coolant bypasses the radiator providing for coolant pressure and flow control. The Heater Core Shut Off valve has a single purpose which is to limit coolant flow for fast engine warm-up. The ATWU-C valve will transfer engine coolant from the sub-radiator to the Transmission Oil Cooler (TOC) when energized, resulting in a heat transfer from the transmission into the engine coolant (over-temperature control of the transmission). The ATWU-H valve is used to provide hot engine coolant to the TOC to improve transmission fluid temperature control.

The Coolant Bypass Valve output circuit is checked for opens and shorts (P26B7).

DTCs	P26B7 - Coolant Bypass Valve Solenoid Circuit
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK	Not Applicable
Monitoring Duration	5 seconds

P26B7 (Coolant Bypass Valve Solenoid Circuit): open/shorted

The Heater Core Shut-Off Valve output circuit is checked for opens and shorts (P26BD).

DTCs	P26BD - Heater Core Shut-Off Valve Solenoid Circuit
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK	Not Applicable
Monitoring Duration	5 seconds

P26BD (Heater Core Shut-Off Valve Solenoid Circuit): open/shorted

The Active Transmission Heating Valve output circuit is checked for opens and shorts (P2681).

DTCs	P2681 - Active Transmission Heating Valve Solenoid Circuit
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK	Not Applicable
Monitoring Duration	5 seconds

P26B7 (Active Transmission Heating Valve Solenoid Circuit): open/shorted

The Active Transmission Cooling Valve output circuit is checked for opens and shorts (P26AC).

DTCs	P26AC - Active Transmission Cooling Valve Solenoid Circuit
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK	Not Applicable
Monitoring Duration	5 seconds

P26AC (Active Transmission Cooling Valve Solenoid Circuit): open/shorted

Auxiliary Coolant System Pumps 

Some engines will include an auxiliary coolant system pump that is PCM controlled. This is a second cooling pump in the main cooling loop. It is a low power electrically controlled pump which is used to provide engine coolant flow under conditions when the engine is not running and the main mechanical cooling pump is inactive. These auxiliary pumps can be used for two primary purposes: 1) to provide coolant flow through the cabin heat exchanger (heater core) which generates heat for the vehicle cabin (stop/start equipped vehicles), and 2) to provide coolant flow to engine components for the purposes of component protection after the engine is shut-off. On turbo equipped vehicles, engine coolant is used to cool the turbo system bearings resulting in a thermal transfer of heat into the coolant. After-run coolant flow may be required to prevent localized coolant boiling that can damage some cooling system components (particularly the degas bottle).

The auxiliary cooling pump diagnostics include circuit checks for Open (P2600), short-to-power (P2603), short-to-ground (P2602), and a functional performance check (P2601).

DTCs	P2600 - Coolant Pump "A" Control Circuit/Open P2601 - Coolant Pump "A" Control Performance/Stuck Off P2602 - Coolant Pump "A" Control Circuit Low P2603 - Coolant Pump "A" Control Circuit High
Monitor Execution	Continuous
Monitor Sequence	None
Sensors OK	Not Applicable
Monitoring Duration	5 seconds

Entry Condition	Minimum	Maximum
Battery Voltage	11.0 Volts