P0103

P0103-MASS AIR FLOW SENSOR "A" CIRCUIT HIGH




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

The Mass Air Flow 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. This means that it's resistance drops when it's temperature drops. The drop in resistance allows more current to flow through it in order to maintain the programmed temperature. This current is changed to a frequency which is sent to the Engine Control Module (ECM) 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 ECM will light the MIL lamp immediately after this diagnostic runs and fails. The ECM will turn off the MIL lamp when the diagnostic runs and passes in four consecutive drive cycles.

- When Monitored:
When the key is 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 Mass Air Flow Sensor, EGR Airflow Control 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 reset?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.

2. (K157) MAF SENSOR SIGNAL CIRCUIT SHORTED TO BATTERY




1. Turn the ignition off.
2. Disconnect the Mass Air Flow Sensor harness connector.
3. Turn the ignition on.
4. Using a volt meter, measure the voltage of the (K157) MAF Sensor Signal circuit at the MAF Sensor harness connector.

Is 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. (K916) MAF SENSOR RETURN CIRCUIT OPEN




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

Is the resistance below 10.0 Ohms?

Yes

- Go To 4

No

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

4. MAF SENSOR
1. Turn the ignition off.
2. Reconnect the ECM C1 harness connector.
3. Reconnect the MAF Sensor harness connector.
4. Turn the ignition on, engine not running.
5. Clear DTCs.
6. Disconnect the MAF Sensor harness connector and read DTCs.

Does the scan tool display P0102 active?

Yes

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

No

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