Test J: Mass Air Flow (MAF) Sensor
PINPOINT TEST J: MASS AIR FLOW (MAF) SENSORFlow Chart:
This pinpoint test is intended to diagnose the following:
- MAF sensor
- harness circuits: MAF SIG, MAF RTN, vehicle power (VPWR), and power ground (PWRGND)
- Powertrain control module (PCM) (12A650)
MAF/IAT Sensor Connector
MAF/IAT Sensor Connector:
PCM Connector
PCM Connector:
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J1 : PRELIMINARY DIAGNOSIS FOR DIAGNOSTIC TROUBLE CODES (DTCS) P0101, P0103, P1102
- Carry out a visual inspection.
- Retrieve and record all DTCs.
- Clear all the DTCs
- Carry out the KOEO on-demand self-test. Quick Test Description
- Carry out the KOER on-demand self-test. Quick Test Description
- Are DTCs P0101, P0103, or P1102 present?
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J2 : DIAGNOSTIC TROUBLE CODE (DTC) P0101
NOTE: Visually inspect the vehicle for aftermarket accessories and performance modifications (exhaust system, turbocharger, performance chip). Refer to Description and Operation Electronic Engine Control (EEC) System, Modifications to OBD Vehicles. Electronic Engine Control (EEC) System
- Remove and check the MAF sensor for contamination.
- Inspect the CAC hoses and flexible connections for damage or leaks.
- Check the air filter element and housing for blockage.
- Check the air filter housing intake for blockage.
- Is any restriction or contamination present?
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J3 : CHECK THE CHARGE AIR COOLER, AIR INTAKE AND EXHAUST SYSTEMS FOR LEAKS AND RESTRICTIONS
- Ignition OFF.
- Disconnect the hose from the EP sensor.
- Plug the exhaust pipe.
- Connect the Rotunda Smoke Machine, Fuel Evaporative Emission System Tester 218-00001 (522) or equivalent to the EP hose.
- Fill the exhaust system with smoke.
- Pressurize the exhaust system with 20 PSI regulated shop air.
- Disconnect the hose from the MAP sensor.
- Inspect the MAP sensor hose and manifolds for damage, leaks, restrictions, and correct routing.
- Connect the Rotunda Smoke Machine, Fuel Evaporative Emission System Tester 218-00001 (522) or equivalent to the MAP hose.
- Fill the air intake system with smoke.
- Pressurize the air intake system with 20 PSI regulated shop air.
- Check air intake and exhaust systems for leaks.
- Are any leaks or restrictions present?
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J4 : CHECK THE MAF OUTPUT SIGNAL TO THE PCM
NOTE: The calibration limits the engine RPM when using output state control. The engine RPM must be increased using the accelerator pedal to reach the required RPM for this test.
- Ignition ON, engine running.
- Access the PCM and monitor the MAF PID.
- Monitor the MAF PID at idle and record the value.
- Access the PCM and monitor the RPM PID.
- Increase the engine speed to approximately 2,500 RPM while monitoring the MAF PID and record the value.
- Is the MAF PID value 1.2 to 1.8 volts with the engine at idle and 2.4 to 3.0 volts at 2,500 RPM?
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J5 : DIAGNOSTIC TROUBLE CODE (DTC) P1102
NOTE: Refer to the PCM connector pin numbers at the beginning of this pinpoint test.
- Inspect the air intake for restrictions
- Ignition OFF.
- MAF/IAT Sensor connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
- Is the voltage greater than 10.5 V?
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J6 : CHECK THE MAF RTN AND MAF PWRGND FOR AN OPEN
- Measure the voltage between:
- Is the voltage between 5.5 V - 6.5 V?
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J7 : CHECK THE MAF SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- PCM connector disconnected.
- Measure the resistance between:
- Is the resistance greater than 10 kOhm?
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J8 : CHECK THE MAF SENSOR SIGNAL CIRCUIT FOR AN OPEN
- Measure the resistance between:
- Is the resistance less than 5 Ohm?
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J9 : CHECK THE MAF SENSOR SIGNAL
NOTE: This step may cause DTC P0103 to set.
- Ignition OFF.
- PCM connector connected.
- Ignition ON, engine OFF.
- Access the PCM and monitor the MAF PID.
- Record the MAF V PID value
- Connect a 5 amp fused jumper wire between the following:
- Does the MAF PID change from less than 0.04 volts to greater than 4.5 volts?
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J10 : DIAGNOSTIC TROUBLE CODE (DTC) P0103
NOTE: Refer to the PCM and component connector pin numbers at the beginning of this pinpoint test
- Disconnect the air inlet and check for restrictions and water intrusion.
- Is a concern present?
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J11 : SIMULATE THE OPPOSITE SIGNAL
- Ignition OFF.
- MAF/IAT Sensor connector disconnected.
- The MAF/IAT sensor is disconnected to simulate the opposite DTC.
- Ignition ON, engine OFF.
- Carry out the KOER on-demand self-test Quick Test Description
- Is DTC P1102 present?
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J12 : CHECK THE MAF SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- PCM connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
- Is the voltage less than 0.2 V?
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J13 : CHECK THE MAF RETURN CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure the resistance between:
- Is the resistance less than 5 Ohm?
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J14 : CHECK THE MAF SIGNAL TO THE PCM
- Ignition ON, engine running.
- Access the PCM and monitor the MAF PID.
- Monitor the MAF PID at idle and record the value.
- Access the PCM and control the RPM PID.
- Increase the engine speed to approximately 2,500 RPM while monitoring the MAF PID and record the value.
- Is the MAF PID value 1.2 to 1.8 volts with the engine at idle and 2.4 to 3.0 volts at 2,500 RPM?
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J15 : 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?
