Test Dc: Mass Airflow Sensor: Testing
| Fault Code | KOEO | KOER | Continuous Memory |
|---|---|---|---|
| P0102 | DC2 | DC2 | |
| P0103 | DC20 | DC20 | DC20 |
| P1100 | DC16 | ||
| P1101 | DC3 | DC1 |
- 1) For KOER Only DTC P1101: Check For MAF Sensor Continuous Memory DTCs
DTC P1101, retrieved during KOER on-demand self-test, indicates MAF sensor voltage signal was not 0.46-2.44 volts during KOER on-demand self-test. Possible causes for this fault are:- Low Battery Charge
- Contaminated Or Faulty MAF Sensor Or Connector
- Open In PWR GND Circuit To MAF Sensor
- Open In MAF RTN Circuit To MAF Sensor
- Faulty PCM
Drive vehicle for 6-10 minutes and repeat KOER ON-DEMAND SELF-TEST , KOEO ON-DEMAND SELF-TEST and CONTINUOUS MEMORY SELF-TEST . If no Continuous Memory DTCs are present with KOER DTC P1101, turn ignition switch to OFF position and go to step 3). If any Continuous Memory DTCs are present with KOER DTC P1101, proceed as follows:
- For Continuous Memory DTC P0102, go to next step.
- For Continuous Memory DTC P0103, go to step 20).
- All other Continuous Memory DTCs, service DTCs as necessary. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .
- 2) For KOER & Continuous Memory Only DTC P0102: Check MAF Sensor Signal Low Input To PCM
DTC P0102 indicates MAF signal (voltage) fell below the minimum calibrated limit during KOEO or KOER Comprehensive Component Monitor (CCM). Possible causes for this fault are:- MAF Sensor Disconnected
- MAF Circuit Open To PCM
- VPWR Circuit Open To MAF Sensor
- MAF RTN Circuit Open To PCM
- MAF Circuit Shorted To Ground
- Intake Air Leak (Near MAF Sensor)
- Closed Throttle Indication
- Faulty MAF Sensor Or Connector
- Faulty PCM
Check for broken or loose air outlet tube clamps at throttle body and air cleaner assembly. Check for holes and cracks in air outlet tube. Check for worn gaskets between MAF sensor and air cleaner. Repair as necessary. Start engine and allow to idle. Check for KOER DTCs. If KOER DTC P0505 is present, go to TEST KE, step 2) . On A/T models, if engine stalls or cannot maintain idle speed, go to step 7). If KOER DTC P0505 is not present and engine idles okay, raise engine speed to 1500 RPM for 5 seconds, then allow to return to idle. Using scan tool, access MAF V PID from PID/DATA MONITOR & RECORD menu. If MAF V PID voltage is less than .23 volt, go to step 4). If MAF V PID voltage is .23 volt or more, go to next step.
- 3) For KOEO Only DTC P1101: Check For MAF Sensor Signal Out Of Self-Test Range
DTC P1101, retrieved during KOEO on-demand self-test, indicates MAF sensor voltage signal was more than 0.27 volts during KOEO on-demand self-test. Possible causes for this fault are:- Low Battery Charge
- Contaminated Or Faulty MAF Sensor Or Connector
- Open In PWR GND Circuit To MAF Sensor
- Open In MAF RTN Circuit To MAF Sensor
- Faulty PCM
Ensure MAF sensor is connected properly. Repair as necessary. Start engine and allow to idle. Using scan tool, access MAF V PID from PID/DATA MONITOR & RECORD menu. If MAF V PID voltage is .46-2.44 volts, no concern is indicated at this time. Check for intermittent concern. Go to TEST Z, step 1) . If MAF V PID voltage is not .46-2.44 volts, go to next step.
- 4) Check VPWR Voltage To MAF Sensor
Turn ignition switch to OFF position. Disconnect MAF sensor. Turn ignition switch to ON position. Using a DVOM, measure voltage between negative battery terminal and MAF sensor harness connector VPWR terminal. See Figure, Figure and Fig 2-Fig 4 . If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, locate and repair open in VPWR circuit. - 5) Check PWR GND Circuit Between MAF Sensor & Power Relay
Using a DVOM, measure voltage between positive battery terminal and MAF sensor harness connector PWR GND terminal. See Figure, Figure and Fig 2-Fig 4 . If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, locate and repair open in PWR GND circuit. - 6) Check MAF Circuit For Short To PWR GND Or MAF RTN In Harness
Ensure PCM is disconnected. Disconnect scan tool from Data Link Connector (DLC). Using a DVOM, measure resistance between MAF and PWR GND, and MAF RTN circuits at MAF sensor harness connector. See Figure, Figure and Fig 2-Fig 4 . If both resistance measurements are more than 10 k/ohms, go to next step. If either resistance measurement is 10 k/ohms or less, repair short to ground in affected circuit. - 7) Check MAF RTN Circuit For Short To PWR GND In Harness
Using a DVOM, measure resistance between MAF RTN and PWR GND circuits at MAF sensor harness connector. See Figure, Figure and Fig 2-Fig 4 . If resistance measurement is more than 10 k/ohms, reconnect scan tool and go to next step. If resistance measurement is 10 k/ohms or less, repair short to ground in affected circuit. - 8) Check MAF Circuit For Short To PWR GND In The PCM
Reconnect PCM. Using DVOM, measure resistance between MAF and PWR GND circuits at the MAF sensor harness connector. See Figure, Figure and Fig 2-Fig 4 . If resistance is greater than 10,000 ohms, reconnect scan tool and go to next step. If resistance is equal to or less than 10,000 ohms, replace PCM. - 9) Check MAF Circuit Voltage Cycling Integrity
Turn ignition switch to ON position. Using scan tool, access MAF V PID from PID/DATA MONITOR & RECORD menu. Record MAF V PID reading. Connect a jumper wire between MAF sensor harness connector MAF RTN and PWR GND terminals, and another jumper wire between MAF sensor harness connector VPWR and MAF terminals. See Figure, Figure and Fig 2-Fig 4 . If MAF V PID reading changes from less than .23 volt to more than 4.5 volts, replace MAF sensor. If MAF V PID reading does not change from less than .23 volt to more than 4.5 volts, proceed as follows:- If DTC P1101 is present without DTC P0102, go to step 11).
- If DTC P0102 is only DTC present, go to next step.
- 10) Check MAF Circuit For Open
Turn ignition switch to OFF position. Disconnect PCM connector(s). Using a DVOM, measure resistance of MAF circuit between MAF sensor harness connector and PCM harness connector. See Figure, Figure and Fig 2-Fig 4 . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in MAF circuit. - 11) Check PWR GND Circuit For Open In Harness
Ensure ignition switch is turned to OFF position. Disconnect PCM connector(s). Disconnect scan tool from Data Link Connector (DLC). Using a DVOM, measure resistance of PWR GND circuit between MAF sensor harness connector and negative battery terminal. If resistance is less than 10 ohms, reconnect scan tool to DLC and go to next step. If resistance is 10 ohms or more, repair open in PWR GND circuit. - 12) Check MAF RTN Circuit For Open In Harness
Using a DVOM, measure resistance of MAF RTN circuit between MAF sensor harness connector and PCM harness connector. See Figure, Figure and Fig 2-Fig 4 . If resistance is less than 5 ohms, replace PCM. If resistance is 5 ohms or more, repair open in MAF RTN circuit.NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 12) to step 16). No test procedures have been omitted. - 16) For Continuous Memory Only DTC P1100: Check MAF Circuit For Intermittent Voltage To PCM
DTC P1100 indicates MAF signal exceeded maximum or fell below minimum calibrated limit during the last 40 warm-up cycles. Possible causes for this fault are:- Poor Continuity Through MAF Sensor Connector(s) Or Harness
- Intermittent Open Or Short In MAF Sensor
Start engine and allow to idle. If idle is not stable, see appropriate symptom under SYMPTOMS in TROUBLE SHOOTING - NO CODES - CNG, FLEX-FUEL & GASOLINE article. Raise engine speed to 1500 RPM for 5 seconds, then allow to return to idle. Using scan tool, access MAF V PID from PID/DATA MONITOR & RECORD menu. While observing MAF V PID, tap on MAF sensor and wiggle sensor harness connector to simulate road shock. If MAF V PID voltage reading fluctuates to less than .23 volt (minimum), or to more than 4.6 volts (maximum), inspect MAF sensor connector. Repair connector as necessary. If connector is okay, replace MAF sensor. If MAF V PID voltage reading does not fluctuate to less than .23 volt (minimum), or to more than 4.6 volts (maximum), go to next step.
- 17) Check MAF Sensor Circuit For Intermittent Opens Or Shorts
Turn ignition switch to ON position. Using scan tool, access MAF V PID from PID/DATA MONITOR & RECORD menu. While observing MAF V PID, wiggle small sections of wiring harness starting at MAF sensor working toward PCM. If MAF V PID voltage reading changes to less than .23 volt (minimum), or to more than 4.6 volts (maximum), repair wiring harness as necessary. If MAF V PID voltage reading does not change to less than .23 volt (minimum), or to more than 4.6 volts (maximum), no concern is indicated at this time. Turn ignition switch to OFF position and go to TEST Z, step 1) .NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 17) to step 20). No test procedures have been omitted. - 20) For KOEO, KOER & Continuous Memory DTC P0103: Check MAF Sensor Signal High Input To PCM
DTC P0103 indicates MAF signal exceeded maximum calibrated limit during KOEO or KOER Comprehensive Component Monitor (CCM). Possible causes for this fault are:- Restricted (not blocked) MAF Sensor Screen
- MAF Circuit Shorted To VPWR
- Faulty MAF Sensor Or Connector
- Faulty PCM
Ensure air induction system is free of restrictions. Repair as necessary. Start engine and allow to idle. If KOER DTC P0505 is present, go to TEST KE, step 2) . Raise engine speed to 1500 RPM for 5 seconds then allow to return to idle. Using scan tool, access MAF V PID from PID/DATA MONITOR & RECORD menu. Ensure an incorrect MAF V PID reading of more than 4.60 volts still exists. Turn ignition switch to OFF position. Disconnect MAF sensor connector. Connect a jumper wire between MAF sensor harness connector PWR GND and MAF RTN terminals. See Figure, Figure and Fig 2-Fig 4 . Start engine and allow to idle. If MAF V PID reading does not drop to less than .23 volt, turn ignition switch to OFF position, disconnect jumper wire and go to next step. If MAF V PID reading drops to less than .23 volt, turn ignition switch to OFF position. Remove jumper wire and replace MAF sensor.
- 21) Check MAF Circuit For Short To VPWR In Harness
Leave ignition switch turned to OFF position and MAF sensor disconnected. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Turn ignition switch to ON position. Using a DVOM, measure voltage between MAF and PWR GND circuits at PCM harness connector. See PCM CONNECTOR IDENTIFICATION and Figure, Figure and Fig 2-Fig 4 . If voltage is less than one volt and an idle concern is not present, replace PCM. If voltage is less than one volt and an idle concern is still present, disregard DTC P0102 at this time and see SYMPTOMS in TROUBLE SHOOTING - NO CODES - CNG, FLEX-FUEL & GASOLINE article. If voltage is one volt or more, repair MAF circuit for short to power.NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 21) to step 25). No test procedures have been omitted. - 25) DTC P0171, P0172, P0174, P0175, P1130, P1131, P1132, P1150, P1151, P1152, P2195, P2196, P2197, P2198 Or Lean Driveability Concerns: Check Lean Conditions Related To MAF Sensor
DTCs P0171, P0172, P0174, P0175, P2195, P2196, P2197 or P2198 indicate a concern when adaptive fuel strategy senses a lean or rich condition beyond the minimum or maximum calibrated limit. DTCs P1130 and P1150 indicate when an HO2S fails to switch due to a circuit or fuel exceeding a calibrated limit. DTCs P1131, P1132, P1151 and P1152 indicate a concern when fuel control system does not detect HO2S switching for a calibrated time. Possible causes for these faults are:- Air Measurement System
MAF sensor contaminated, damaged or malfunctioning. - Fuel System
Fuel pressure regulator is leaking or malfunctioning. Fuel filter plugged or dirty. Fuel pump is weak or check valve leaking. Leaking or contaminated fuel injectors. Low fuel pressure or running out of fuel. EVAP canister purge valve leaking (when canister is "clean"). Fuel supply line restricted. Fuel rail pressure sensor (incorrect reading). - Air Induction System
Air leaks after MAF sensor, vacuum leaks, PCV system leaking or sticking valve, or improperly seated engine oil dipstick. - Exhaust System
Exhaust leaks before or near HO2S, such as; exhaust manifold gasket or mating gaskets. - EGR System
Leaking EGR valve gasket or tube, stuck EGR valve, leaking diaphragm or EVR solenoid leaking vacuum. - Secondary Air Injection
Damaged or malfunctioning secondary air injection system (mechanically stuck valve). - Engine Mechanical
Engine oil overfilled, cam timing, cylinder compression or exhaust leaks before or near HO2S.
Ensure MAF sensor is connected. Start engine and bring to normal operating temperature. Using scan tool, access BARO, LONGFT1, LONGFT2 and MAF V PIDs. Check the following:
- Ensure BARO PID is about the same as barometric pressure measurement for location, day and altitude of area. See Fig 5.
- Ensure BARO PID values in Keep Alive Memory have been updated. If vehicle is driven down from higher altitudes for diagnosing, complete 3 or 4 heavy accelerations at more than 1/2 throttle to allow BARO PID to update.
- Ensure BARO PID is within plus or minus 6 Hz (plus or minus 2 in. Hg) of altitude value. Refer to illustration. See Fig 5.
- Ensure LONGFT1, LONGFT2 PIDs for all injector banks at idle are not more than minus 12 percent.
- Ensure MAF V PID at idle in gear or neutral is not more than 30 percent (no more than 1.1 volt) of normal MAF V listed in appropriate pin voltage/PID value chart in appropriate PIN VOLTAGE/PID VALUE CHARTS article.
If 2 out of the 3 checks are not within specification, go to next step. If 2 out of the 3 checks are within specification and DTCs P0171, P0172, P0174, P0175, P1130, P1131, P1132, P1150, P1151, P1152, P2195, P2196, P2197 or P2198 are present, go to TEST H, step 42) (gasoline vehicles), or TEST HA, step 42) (natural gas vehicles). If 2 out of the 3 checks are within specification and no DTCs are present but driveability concern still exists, diagnose by symptom. See SYMPTOMS in TROUBLE SHOOTING - NO CODES - CNG, FLEX-FUEL & GASOLINE article.
- Air Measurement System
- 26) Check To Isolate MAF Sensor From Lean Driveability Occurrence
Disconnect MAF sensor connector. Start engine and drive vehicle. If lean driveability symptom (lack of power, spark knock, detonation, buck, jerk or hesitation on acceleration) is gone, replace MAF sensor. If lean driveability symptom still exists and DTCs P0171, P0172, P0174, P0175, P1130, P1131, P1132, P1150, P1151 or P1152 are present, go to TEST H, step 42) (gasoline vehicles), or TEST HA, step 42) (natural gas vehicles). If lean driveability symptom did not disappear and no DTCs are present, diagnose by symptom. See SYMPTOMS under TROUBLE SHOOTING - NO CODES - CNG, FLEX-FUEL & GASOLINE article.