P0100-MASS AIR FLOW SENSOR
For a complete wiring diagram Refer to Section 8W
Possible Causes
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INTERMITTENT DTC
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(K157) MASS AIR FLOW SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
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(K957) MASS AIR FLOW SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE
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(F344) FUSED ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE
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(K157) MASS AIR FLOW SENSOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
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(K957) MASS AIR FLOW SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE
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(K157) MASS AIR FLOW SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
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(K157) MASS AIR FLOW SENSOR SIGNAL CIRCUIT SHORTED TO THE (K957) MASS AIR FLOW SENSOR GROUND CIRCUIT
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MASS AIR FLOW SENSOR
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ENGINE CONTROL MODULE (ECM)
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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.
(F344) FUSED ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE
Using a 12 volt test light connected to ground, check the (F344) Fused ASD Relay Output circuit in the Mass Air Flow Sensor harness connector.
NOTE:
The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Is the test light illuminated and bright?
Yes
No
5.
(K157) MASS AIR FLOW SENSOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
Turn the ignition off.
Disconnect the ECM harness connector.
Measure the resistance of the (K157) Mass Air Flow Sensor Signal circuit between the Mass Air Flow Sensor harness connector and the Engine Control Module (ECM) harness connector.
Is the resistance below 10.0 ohms?
Yes
No
6.
(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 harness connector and the Engine Control Module (ECM) harness connector.
Is the resistance below 10.0 ohms?
Yes
No
7.
(K157) MASS AIR FLOW SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (K157) Mass Air Flow Sensor Signal circuit in the Mass Air Flow Sensor harness connector.
Is the resistance above 1000 ohms?
Yes
No
8.
(K157) MASS AIR FLOW SENSOR SIGNAL CIRCUIT SHORTED TO THE (K957) MASS AIR FLOW SENSOR GROUND CIRCUIT
Measure the resistance between the (K157) Mass Air Flow Sensor Signal circuit and the (K957) Mass Air Flow Sensor Ground circuit in the Mass Air Flow Sensor harness connector.
Is the resistance above 1000 ohms?
Yes
No
9.
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
10.
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