Test Procedure

DC1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS)

Are DTCs P0102, P0103, P0104, P1100, or P1101 present?

Yes	No
For KOER and continuous memory DTC P0102, P0104, GO to DC5. For DTC P0103, GO to DC21. For KOEO DTC P1101, GO to DC7. For KOER and continuous memory DTC P1101, GO to DC2. For continuous memory DTC P1100, GO to DC19.	For all other symptoms without DTCs, GO to DC27.

DC2 DTC P1101: CHECK FOR MAF SENSOR CONTINUOUS MEMORY DTCS

Retrieve continuous memory DTCs.
Is a continuous memory MAF DTC present with the KOER DTC P1101?

Yes	No
GO to DC3.	GO to DC5.

DC3 VERIFY CONTINUOUS MEMORY DTC P0102

Is a continuous memory DTC P0102 present with the KOER DTC P1101?

Yes	No
GO to DC5.	GO to DC4.

DC4 VERIFY CONTINUOUS MEMORY DTC P0103

Is a continuous memory DTC P0103 present with the KOER DTC P1101?

Yes	No
GO to DC21.	All other continuous memory DTCs: DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO toDIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .

DC5 KOER AND CONTINUOUS MEMORY DTCS P0102, P0104 OR P1101: CHECK THE INTAKE AIR SYSTEM FOR LEAKS, OBSTRUCTIONS, AND DAMAGE

Key in OFF position.
Check the air inlet system (air cleaner, housing, duct work) for obstructions or blockage.
Check for broken/loose air outlet tube clamps (throttle body and air cleaner assembly ends), cracks/holes in the air outlet tube, and worn gaskets between the MAF sensor and the air cleaner assembly. Check the throttle body bore for sludge. Verify the MAF sensor is connected. Repair as necessary.
Are there any concerns found during the visual inspection?

Yes	No
REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test.	GO to DC6.

DC6 CHECK THE MAF PID

Access the PCM and monitor the RPM PID.
Run the engine up to 1,500 RPM for 5 seconds, then bring it back to idle.
Access the PCM and monitor the MAF PID.
Is the voltage less than 0.23 V?

Yes	No
GO to DC9.	GO to DC7.

DC7 CHECK THE MAF SIGNAL SENT TO THE PCM

NOTE: DTC P1101 can be generated by a low charged vehicle battery or the garage exhaust ventilation system. Charge the battery as necessary, then remove the ventilation system and properly vent to the outside atmosphere. Check the air inlet system (air cleaner, housing, duct work) for obstructions or blockage. Repeat the KOEO self-test.

Key in OFF position.
MAF/IAT Sensor connector connected.
Key ON, engine OFF.
Access the PCM and monitor the MAF PID.
Is the voltage less than 0.2 V?

Yes	No
GO to DC8.	GO to DC9.

DC8 CHECK THE MAF SIGNAL SENT TO THE PCM

Key ON, engine running.
Access the PCM and monitor the MAF PID.
Is the voltage between 0.46 - 2.44 V?

Yes	No
Unable to identify the concern at this time. refer to PINPOINT TEST Z .	GO to DC9.

DC9 CHECK THE VPWR TO THE MAF SENSOR

Key in OFF position.
MAF/IAT Sensor connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) MAF/IAT Sensor Connector, Harness Side	( - ) Vehicle Battery
VPWR - Pin 6	Negative terminal

Is the voltage greater than 10 V?

Yes	No
GO to DC10.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

DC10 CHECK THE PWRGND CIRCUIT TO THE MAF SENSOR

Measure the voltage between:

( + ) Vehicle Battery	( - ) MAF/IAT Sensor Connector, Harness Side
Positive terminal	PWRGND - Pin 5

Is the voltage greater than 10 V?

Yes	No
GO to DC11.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

DC11 CHECK FOR SHORTS BETWEEN THE CIRCUITS IN THE MAF HARNESS

Key in OFF position.
MAF/IAT Sensor connector disconnected.
PCM connector disconnected.

Measure the resistance between:

( + ) MAF/IAT Sensor Connector, Harness Side	( - ) MAF/IAT Sensor Connector, Harness Side
MAF - Pin 3	PWRGND - Pin 5
MAF - Pin 3	MAF RTN - Pin 4
MAF - Pin 3	SIGRTN - Pin 2
MAF - Pin 3	IAT - Pin 1

Are the resistances greater than 10K ohms?

Yes	No
GO to DC12.	REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.

DC12 CHECK THE MAF RTN CIRCUIT FOR AN OPEN IN THE HARNESS

Measure the resistance between:

( + ) PCM Connector, Harness Side	( - ) MAF/IAT Sensor Connector, Harness Side
MAF RTN	MAF RTN - Pin 4

Is the resistance less than 5 ohms?

Yes	No
GO to DC13.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

DC13 CHECK THE MAF RTN CIRCUIT FOR A SHORT TO PWRGND IN THE HARNESS

Measure the resistance between:

( + ) MAF/IAT Sensor Connector, Harness Side	( - ) MAF/IAT Sensor Connector, Harness Side
MAF RTN - Pin 4	PWRGND - Pin 5

Is the resistance greater than 10K ohms?

Yes	No
GO to DC14.	REPAIR the short circuit to GND. CLEAR the DTCs. REPEAT the self-test.

DC14 CHECK THE MAF CIRCUIT FOR A SHORT TO PWRGND IN THE PCM

PCM connector connected.

Measure the resistance between:

( + ) MAF/IAT Sensor Connector, Harness Side	( - ) MAF/IAT Sensor Connector, Harness Side
MAF - Pin 3	PWRGND - Pin 5

Is the resistance greater than 10K ohms?

Yes	No
GO to DC15.	GO to DC31.

DC15 CHECK THE MAF CIRCUIT VOLTAGE CYCLING INTEGRITY

Key ON, engine OFF.
Access the PCM and monitor the MAF PID.

Connect a 5 amp fused jumper wire between the following:

Point A MAF/IAT Sensor Connector, Harness Side	Point B MAF/IAT Sensor Connector, Harness Side
MAF RTN - Pin 4	PWRGND - Pin 5
MAF - Pin 3	VPWR - Pin 6

Record the PID reading while both jumpers are installed.
Remove the VPWR jumper while observing the MAF PID.
Does the MAF PID change from greater than 4.50 volts to less than 0.26 volt when the VPWR jumper is removed?

Yes	No
INSTALL a new MAF/IAT sensor. REFER to the ELECTRONIC ENGINE CONTROLS - GASOLINE ENGINES articles. RESETTING THE KEEP ALIVE MEMORY (KAM) .	GO to DC16.

DC16 CHECK THE MAF CIRCUIT FOR AN OPEN IN THE HARNESS

Key in OFF position.
Remove the jumper wire(s).
PCM connector disconnected.

Measure the resistance between:

( + ) PCM Connector, Harness Side	( - ) MAF/IAT Sensor Connector, Harness Side
MAF	MAF - Pin 3

Is the resistance less than 5 ohms?

Yes	No
GO to DC17.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

DC17 CHECK THE PWRGND CIRCUIT FOR AN OPEN IN THE HARNESS

PCM connector disconnected.

Measure the resistance between:

( + ) MAF/IAT Sensor Connector, Harness Side	( - ) Vehicle Battery
PWRGND - Pin 5	Negative terminal

Is the resistance less than 5 ohms?

Yes	No
GO to DC18.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

DC18 CHECK THE MAF RTN CIRCUIT FOR AN OPEN IN THE HARNESS

Measure the resistance between:

( + ) PCM Connector, Harness Side	( - ) MAF/IAT Sensor Connector, Harness Side
MAF RTN	MAF RTN - Pin 4

Is the resistance less than 5 ohms?

Yes	No
GO to DC31.	REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.

DC19 DTC P1100: CHECK THE MAF CIRCUIT FOR INTERMITTENT VOLTAGE TO THE PCM

Check for broken/loose air outlet tube clamps (throttle body and air cleaner assembly ends), cracks/holes in the air outlet tube, and worn gaskets between the MAF sensor and the air cleaner assembly. Verify the MAF sensor is connected.
Key ON, engine running.
Access the PCM and monitor the MAF PID.
If idle is not stable, refer to NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX .
Access the PCM and monitor the RPM PID.
Run the engine up to 1,500 RPM for 5 seconds, then bring it back to idle.
Lightly tap on the MAF sensor and wiggle the harness connector to simulate road shock.
Does the MAF PID go below 0.23 volt or above 4.6 volts?

Yes	No
INSPECT the MAF/IAT sensor connector. If OK, INSTALL a new MAF/IAT sensor. REFER to the ELECTRONIC ENGINE CONTROLS - GASOLINE ENGINES articles.RESETTING THE KEEP ALIVE MEMORY (KAM) .	GO to DC20.

DC20 CHECK THE MAF CIRCUIT FOR AN INTERMITTENT OPEN OR SHORTS

Key ON, engine running.
Access the PCM and monitor the MAF PID.
Wiggle, shake, and bend small sections of the wiring harness while working from the sensor to the PCM.
Does the MAF PID go below 0.23 volt or above 4.6 volts?

Yes	No
REPAIR as necessary. RESET the keep alive memory (KAM). REFER toRESETTING THE KEEP ALIVE MEMORY (KAM) .	Unable to duplicate or identify the concern at this time. CLEAR the DTCs. REPEAT the self-test.

DC21 DTC P0103: CHECK THE MAF SENSOR SCREEN FOR CONTAMINATION

NOTE: DTC P0103 can be generated by foreign material blocking the MAF sensor screen, causing an air flow restriction.

Check the MAF sensor screen for contamination or blockage.
Check the air cleaner element and air tubes for proper installation and sealing.
Are any concerns present?

Yes	No
REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test.	GO to DC22.

DC22 DTC P0103: CHECK THE MAF SENSOR SIGNAL HIGH INPUT TO THE PCM

Key ON, engine OFF.
Access the PCM and monitor the MAF PID.
Is the voltage greater than 2.44 V?

Yes	No
GO to DC23.	GO to DC25.

DC23 CHECK THE MAF SENSOR SIGNAL SENT TO THE PCM

Key in OFF position.
MAF/IAT Sensor connector disconnected.

Connect a 5 amp fused jumper wire between the following:

Point A MAF/IAT Sensor Connector, Harness Side	Point B MAF/IAT Sensor Connector, Harness Side
MAF RTN - Pin 4	PWRGND - Pin 5

Key ON, engine OFF.
Access the PCM and monitor the MAF PID.
Is the voltage less than 0.1 V?

Yes	No
CHECK the MAF/IAT sensor electrical connector for damage, corrosion, and water ingress. If OK, INSTALL a new MAF/IAT sensor. REFER to the ELECTRONIC ENGINE CONTROLS - GASOLINE ENGINES articles. RESETTING THE KEEP ALIVE MEMORY (KAM) .	GO to DC24.

DC24 CHECK THE MAF CIRCUIT FOR A SHORT TO VOLTAGE

Key in OFF position.
PCM connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) PCM Connector, Harness Side	( - )
MAF	Ground

Is the voltage less than 1 V?

Yes	No
GO to DC26.	REPAIR the short circuit to PWR. CLEAR the DTCs. REPEAT the self-test.

DC25 CHECK THE MAF SIGNAL SENT TO THE PCM

Key ON, engine running.
Access the PCM and monitor the RPM PID.
Monitor the MAF signal voltage while increasing the engine RPM from idle to approximately 2,500 RPM, and then back to idle.
Access the PCM and monitor the MAF PID.
Is the voltage between 0.23 - 4.6 V?

Yes	No
This is an intermittent concern. refer to PINPOINT TEST Z .	GO to DC23.

DC26 VERIFY THE IDLE CONCERN

PCM connector connected.
MAF/IAT Sensor connector connected.
Key ON, engine running.
Is an idle concern present?

Yes	No
DISREGARD DTC P0103 at this time. The concern is elsewhere. RETURN toNO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX to diagnose unique idle concerns.	GO to DC31.

DC27 SYMPTOMS WITHOUT DTCS: CHECK THE CONDITIONS RELATED TO THE MAF SENSOR

Check the air inlet system (air cleaner, housing, duct work) for obstructions or blockage.
Check for broken/loose air outlet tube clamps (throttle body and air cleaner assembly ends), cracks/holes in the air outlet tube, and worn gaskets between the MAF sensor and the air cleaner assembly. Verify the MAF sensor is connected.
Is a concern present?

Yes	No
REPAIR as necessary. RESET the keep alive memory (KAM). REFER toRESETTING THE KEEP ALIVE MEMORY (KAM) .	GO to DC28.

DC28 DTCS P0171, P0172, P0174, P0175, P2195, P2196, P2197 OR P2198: CHECK THE FUNCTIONALITY OF THE MAF SENSOR

NOTE: A MAF PID value of less than 0.6 volt may indicate an incorrectly installed air cleaner or a leak in the air inlet system.

Key ON, engine running.
Allow the engine to stabilize at the correct operating temperature.
Access the PCM and monitor the MAF PID.
Check that the MAF PID at idle and NEUTRAL is not greater than 30% of the normal MAF listed in the REFERENCE VALUES article, Reference Values or not greater than 1.3 volts.
Is the PID value within the expected range?

Yes	No
GO to DC30.	GO to DC29.

DC29 CHECK TO ISOLATE THE MAF SENSOR FROM A LEAN DRIVEABILITY OCCURRENCE

NOTE: Due to increasingly stringent emission/OBD requirements, a fuel system DTC on some vehicles can be generated without a noticeable driveability concern with or without the MAF sensor disconnected. Under these conditions, if the MAF PID indicates a MAF sensor concern, install a new MAF sensor. Refer to the ELECTRONIC ENGINE CONTROLS - GASOLINE ENGINES articles.

Key in OFF position.
MAF/IAT Sensor connector disconnected.
Key ON, engine running.
Drive the vehicle on the road.
Is the lean driveability symptom (lack of power, spark knock/detonation, buck/jerk or hesitation/surge on acceleration) gone?

Yes	No
INSTALL a new MAF/IAT sensor. REFER to the ELECTRONIC ENGINE CONTROLS - GASOLINE ENGINES articles. RESETTING THE KEEP ALIVE MEMORY (KAM) .	GO to DC30.

DC30 VERIFY THE DTC

Are any of the following DTCs present:
P0171, P0172, P0174, P0175, P2195, P2196, P2197, or P2198?

Yes	No
Unable to duplicate or identify the concern at this time. refer to PINPOINT TEST Z .	The concern is elsewhere. RETURN toNO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX to diagnose performance while driving concerns.

DC31 CHECK FOR CORRECT PCM OPERATION

Disconnect all the PCM connectors.
Visually inspect for:
- pushed out pins
- corrosion
Connect all the PCM connectors and make sure they seat correctly.
Carry out the PCM self-test and verify the concern is still present.
Is the concern still present?

Yes	No
INSTALL a new PCM. REFER toFLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) , Programming the VID Block for a Replacement PCM.	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.