P0103-MASS AIR FLOW SENSOR CIRCUIT HIGH





For a complete wiring diagram Refer to Section 8W



Possible Causes
INTERMITTENT DTC
(K157) MASS AIR FLOW SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
(K957) MASS AIR FLOW SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE
(K157) MASS AIR FLOW SENSOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
(K957) MASS AIR FLOW SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE
MASS AIR FLOW SENSOR
ENGINE CONTROL MODULE (ECM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)



Diagnostic Test

1. DTC IS ACTIVE

NOTE: If any Sensor Reference or Sensor Supply voltage DTCs are present, perform the applicable diagnostic procedure before continuing with this test.


Ignition on, engine not running.
With the scan tool, Clear DTCs in the Engine Control Module (ECM).
Start the engine and allow it to reach normal operating temperature.
With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes


No

2. (K157) MASS AIR FLOW SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE



Turn the ignition off.
Disconnect the Mass Air Flow Sensor harness connector.
Turn the ignition on.
Measure the voltage of the (K157) Mass Air Flow Sensor Signal circuit in the Mass Air Flow Sensor harness connector.

Is there any voltage present?

Yes


No

3. (K957) MASS AIR FLOW SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE



Measure the voltage of the (K957) Mass Air Flow Sensor Ground circuit in the Mass Air Flow Sensor harness connector.

Is there any voltage present?

Yes


No

4. (K157) MASS AIR FLOW SENSOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE



Turn the ignition off.
Disconnect the Engine Control Module (ECM) harness connector.
Measure the resistance of the (K157) Mass Air Flow Sensor Signal circuit between the Mass Air Flow Sensor connector and the Engine Control Module (ECM) harness connector.

Is the resistance below 10.0 ohms?

Yes


No

5. (K957) MASS AIR FLOW SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE



Measure the resistance of the (K957) Mass Air Flow Sensor Ground circuit between the Mass Air Flow Sensor connector and the Engine Control Module (ECM) harness connector.

Is the resistance below 10.0 ohms?

Yes


No

6. MASS AIR FLOW SENSOR

Connect the Engine Control Module (ECM) harness connector.
Replace the Mass Air Flow Sensor in accordance with the Service Information.
Turn the ignition on.
With the scan tool, Clear DTCs.
Start the engine and allow it to reach normal operating temperature.
With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes


No

7. ENGINE CONTROL MODULE (ECM)

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Mass Air Flow Sensor and the Engine Control Module (ECM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes


No