P0103

P0103-MASS AIR FLOW SENSOR "A" CIRCUIT HIGH




For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation

The Mass Air Flow (MAF) Sensor is a frequency based device. A constant voltage is applied to a heated wire. This wire is positioned in the air stream and is heated by the electrical current that the voltage produces. As air flows across it, it cools down. The heated wire or film is a Positive Temperature Coefficient (PTC) resistor, which means that the resistance of it drops when the temperature drops. The drop in resistance allows more current to flow through it in order to maintain the programmed temperature. The current flow is changed to a frequency, which is sent to the Powertrain Control Module (PCM) and interpreted as air flow. Adjustments for air temperature and humidity are taken into consideration, since they also affect the temperature of the heated wire or film. The engine running monitor compares an estimated fresh air flow value to the Mass Air Flow Sensor reading. The PCM will light the Malfunction Indicator Lamp (MIL) immediately after this diagnostic runs and fails. The PCM will turn off the MIL when the diagnostic runs and passes in four consecutive drive cycles.

- When Monitored:
When the PCM is powered on.

- Set Condition:
The frequency detected is above what is allowable for the sensor.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC

NOTE: The MAF Sensor, EGR Cooler Bypass Valve and Turbocharger Actuator get a 12V power supply from the Smart Power Relay.

1. Ignition on, engine not running.
2. Record freeze frame data and clear DTCs.
3. Turn the ignition off for one minute.
4. Turn the ignition on.
5. With the scan tool, read DTCs.

Did the DTC return?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test

2. CHECK THE (K157) MAF SENSOR SIGNAL CIRCUIT SHORT TO VOLTAGE




1. Turn the ignition off.
2. Disconnect the MAF Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (K157) MAF Sensor Signal circuit in the MAF Sensor harness connector.

Is the voltage equal to battery voltage?

Yes

- Repair the short to battery in the (K157) MAF Sensor Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 3

3. CHECK THE (K916) MAF SENSOR RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE




1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Measure the resistance of the (K916) MAF Sensor Return circuit between the MAF Sensor harness connector and the PCM C1 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 4

No

- Repair the (K916) MAF Sensor Return circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

4. CHECK THE MASS AIR FLOW SENSOR
1. Turn the ignition off.
2. Reconnect the PCM C1 harness connector.
3. Reconnect the MAF Sensor harness connector.
4. Turn the ignition on, engine not running.
5. With the scan tool, clear DTCs.
6. Disconnect the MAF Sensor harness connector and read DTCs.

Does the scan tool display DTC P0102 as active?

Yes

- Replace the MAF Sensor.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Replace the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.