DC - Test
DC: Mass Air Flow (MAF) Sensor
DC: Introduction DC - Introduction
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DC1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS)
Are any of the following DTCs present during the PCM self-test: P0102, P0103, P0104, or P1101?
YES
For DTC P0102, GO to DC3
.
For DTC P0103, GO to DC19
.
For continuous memory DTC P0104, GO to DC5
.
For KOEO DTC P1101, GO to DC7
.
For KOER DTC P1101, GO to DC2.
NO
GO to DC25.
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DC2 DTC P1101: CHECK FOR MAF SENSOR CONTINUOUS MEMORY DTCS
- Retrieve any continuous memory DTCs.
Is a continuous memory MAF DTC present with the KOER DTC P1101?
YES
GO to DC3.
NO
GO to DC5.
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DC3 VERIFY THE CONTINUOUS MEMORY DTC P0102
Is a continuous memory DTC P0102 present with the KOER DTC P1101?
YES
GO to DC5.
NO
GO to DC4.
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DC4 VERIFY THE CONTINUOUS MEMORY DTC P0103
Is a continuous memory DTC P0103 present with the KOER DTC P1101?
YES
GO to DC19.
NO
DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to Diagnostic Trouble Code (DTC) Charts and Descriptions Diagnostic Trouble Code Descriptions.
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DC5 KOER AND CONTINUOUS MEMORY DTCS P0102, P0104 OR P1101: CHECK THE INTAKE AIR SYSTEM FOR LEAKS, OBSTRUCTIONS, AND DAMAGE
- Check the intake air system (air cleaner, housing, ductwork) 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. Repair as necessary.
Were any concerns found during the visual inspection?
YES
REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test.
NO
GO to DC6.
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DC6 CHECK THE MAF PID
- Start the engine using the engine running diagnostic mode. Refer to Diagnostic Modes Diagnostic Modes.
- Run the engine up to 1,500 RPM for 5 seconds, then bring it back to idle.
- Access the PCM and monitor the RPM PID.
- Access the PCM and monitor the MAF PID.
Is the voltage less than 0.23 V?
YES
GO to DC9.
NO
GO to DC7.
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DC7 CHECK THE MAF SIGNAL
Note: DTC P1101 can be generated by a low charged 12 volt battery or the garage exhaust ventilation system. Repair the 12 volt battery as necessary, then remove the ventilation system and properly vent to the outside atmosphere. Check the intake air system (air cleaner, housing, ductwork) for obstructions or blockage. Repeat the KOEO self-test.
- Key ON, engine OFF.
- Access the PCM and monitor the MAF PID.
Is the voltage less than 0.2 V?
YES
GO to DC8.
NO
GO to DC9.
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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
Unable to identify the concern at this time.
GO to Pinpoint Test Z Z - Introduction.
NO
GO to DC9.
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DC9 CHECK THE VPWR TO THE MAF SENSOR
- MAF/IAT Sensor connector disconnected.
- Key ON, engine OFF.
- Measure the voltage between:
Is the voltage greater than 10.5 V?
YES
GO to DC10.
NO
REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
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DC10 CHECK THE PWRGND CIRCUIT TO THE MAF SENSOR
- Measure the voltage between:
Is the voltage greater than 10.5 V?
YES
GO to DC11.
NO
REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
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DC11 CHECK FOR SHORTS BETWEEN CIRCUITS IN THE MAF HARNESS
- PCM connector disconnected.
- MAF Sensor connector disconnected.
- Measure the resistance between:
Are the resistances greater than 10K ohms?
YES
GO to DC12.
NO
REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
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DC12 CHECK THE MAF RTN CIRCUIT FOR AN OPEN IN THE HARNESS
- Measure the resistance between:
Is the resistance less than 5 ohms?
YES
GO to DC13.
NO
REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
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DC13 CHECK THE MAF RTN CIRCUIT FOR A SHORT TO PWRGND IN THE HARNESS
- Measure the resistance between:
Is the resistance greater than 10K ohms?
YES
GO to DC14.
NO
REPAIR the short circuit to GND. CLEAR the DTCs. REPEAT the self-test.
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DC14 CHECK THE MAF CIRCUIT FOR A SHORT TO PWRGND IN THE PCM
- PCM connector connected.
- Measure the resistance between:
Is the resistance greater than 10K ohms?
YES
GO to DC15.
NO
GO to DC29.
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DC15 CHECK THE MAF CIRCUIT VOLTAGE CYCLING INTEGRITY
- Key ON, engine OFF.
- Access the MAF V PID.
- Connect a 5 amp fused jumper wire between the following:
- Record the PID reading while both jumpers are installed.
- Remove the VPWR jumper while monitoring the MAF V PID.
Does the MAF V PID change from greater than 4.50 volts to less than 0.26 volt when the VPWR jumper is removed?
YES
INSTALL a new MAF/IAT sensor.
Refer to Electronic Engine Controls.
RESET the keep alive memory (KAM).
REFER to Resetting The Keep Alive Memory (KAM) Resetting The Keep Alive Memory (KAM).
CLEAR the DTCs. REPEAT the self-test.
NO
GO to DC16.
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DC16 CHECK THE MAF CIRCUIT FOR AN OPEN IN THE HARNESS
- Key in OFF position.
- PCM connector disconnected.
- Measure the resistance between:
Is the resistance less than 5 ohms?
YES
GO to DC17.
NO
REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
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DC17 CHECK THE PWRGND CIRCUIT FOR AN OPEN IN THE HARNESS
- Measure the resistance between:
Is the resistance less than 5 ohms?
YES
GO to DC18.
NO
REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
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DC18 CHECK THE MAF RTN CIRCUIT FOR AN OPEN IN THE HARNESS
- Measure the resistance between:
Is the resistance less than 5 ohms?
YES
GO to DC29.
NO
REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
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DC19 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
REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test.
NO
GO to DC20.
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DC20 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
GO to DC21.
NO
GO to DC23.
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DC21 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:
- Key ON, engine OFF.
- Access the PCM and monitor the MAF PID.
Is the voltage less than 0.1 V?
YES
REMOVE the jumper wire(s).
CHECK the MAF sensor electrical connector for damage, corrosion, and water intrusion.
If OK, INSTALL a new MAF sensor.
REFER to Electronic Engine Controls.
RESET the keep alive memory (KAM).
REFER to Resetting The Keep Alive Memory (KAM) Resetting The Keep Alive Memory (KAM).
CLEAR the DTCs. REPEAT the self-test.
NO
GO to DC22.
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DC22 CHECK THE MAF CIRCUIT FOR A SHORT TO VOLTAGE
- Key in OFF position.
- PCM connector disconnected.
- Key ON, engine OFF.
- Measure the voltage between:
Is the voltage less than 1 V?
YES
GO to DC24.
NO
REPAIR the short circuit to PWR. CLEAR the DTCs. REPEAT the self-test.
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DC23 CHECK THE MAF SENSOR SIGNAL SENT TO THE PCM
- Start the engine using the engine running diagnostic mode. Refer to Diagnostic Modes Diagnostic Modes.
- Access the PCM and monitor the MAF PID.
- Monitor the MAF signal voltage while increasing the engine RPM from idle to approximately 2,500 RPM, then back to idle.
Is the voltage between 0.23 - 4.6 V?
YES
The concern is intermittent.
GO to Pinpoint Test Z Z - Introduction.
NO
GO to DC21.
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DC24 VERIFY THE IDLE CONCERN
- Start the engine using the engine running diagnostic mode. Refer to Diagnostic Modes Diagnostic Modes.
- PCM connector connected.
- MAF/IAT sensor connector connected.
Is there an idle concern present?
YES
DISREGARD DTC P0103 at this time.
RETURN to Symptom Charts Symptom Related Diagnostic Procedures for further direction.
NO
GO to DC29.
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DC25 SYMPTOMS WITHOUT DTCS: CHECK THE CONDITIONS RELATED TO THE MAF SENSOR
- Check the intake air system (air cleaner, housing, ductwork) 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
REPAIR as necessary.
RESET the keep alive memory (KAM).
REFER to Resetting The Keep Alive Memory (KAM) Resetting The Keep Alive Memory (KAM).
CLEAR the DTCs. REPEAT the self-test.
NO
GO to DC26.
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DC26 DTCS P0171, P0172, P2195 OR P2196: CHECK THE FUNCTIONALITY OF THE MAF SENSOR
Note: A MAF V PID value of less than 0.6 volt may indicate an incorrectly installed air cleaner or a leak in the intake air system.
- Start the engine using the engine running diagnostic mode. Refer to Diagnostic Modes Diagnostic Modes.
- Allow the engine to stabilize at the correct operating temperature.
- Access the PCM and monitor the MAF PID.
- Check that the MAF V PID at idle and neutral is not greater than 30% of the normal MAF V listed in Pinout Values and Diagnostic Parameters Reference Values (or not greater than 2 volts).
Is the PID value within the expected range?
YES
GO to DC28.
NO
GO to DC27.
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DC27 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.
- Key in OFF position.
- MAF/IAT Sensor connector disconnected.
- Key ON, engine running.
- Road test the vehicle.
Is the lean driveability symptom (lack of power, spark knock/detonation, buck/jerk or hesitation/surge on acceleration) gone?
YES
INSTALL a new MAF/IAT sensor.
REFER to Electronic Engine Controls.
RESET the keep alive memory (KAM).
REFER to Resetting The Keep Alive Memory (KAM) Resetting The Keep Alive Memory (KAM).
CLEAR the DTCs. REPEAT the self-test.
NO
GO to DC28.
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DC28 VERIFY THE DTC
Are any of the following DTCs present: P0171, P0172, P2195, P2196?
YES
Unable to duplicate or identify the concern at this time.
GO to Pinpoint Test Z Z - Introduction.
NO
RETURN to Symptom Charts Symptom Related Diagnostic Procedures for further direction.
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DC29 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
INSTALL a new PCM.
REFER to Flash Electrically Erasable Programmable Read Only Memory (EEPROM) Flash Electrically Erasable Programmable Read Only Memory (EEPROM).
NO
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.