P0100
P0100-MASS AIR FLOW SENSOR A
For a complete wiring diagram refer to the Wiring Information Electrical Diagrams
- When Monitored:
If the ignition is on and the ASD1 voltage is greater than 7.5 volts a timer starts. When this timer reaches 0.5 seconds the diagnostic is enabled.
- Set Condition:
The PCM detects a shorted or open condition in the Mass Air Flow Sensor 1 input circuit by checking the frequency signal. If no frequency signal is detected, because the signal is stuck high or stuck low, then this code is reported. One Trip Fault. Three good trips to turn off the MIL.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.Pre-Diagnostic Troubleshooting Procedure
1. DTC IS ACTIVE
NOTE: Diagnose and repair any system voltage or sensor supply voltage DTCs before continuing with this test.
1. Start the engine and allow it to reach normal operating temperature.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose fitting clothing. Failure to follow these instructions can result in personal or fatal injury.
2. With the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go to 2
No
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.Checking for an Intermittent DTC
2. (F342) ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Mass Air Flow Sensor 1 connector.
3. Turn the ignition on.
4. With the scan tool, actuate the Auto Shutdown (ASD) Relay 1 Control State.
5. Using a 12 volt test light connected to ground, check the (F342) ASD Relay Output circuit in the Mass Air Flow Sensor 1 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
- Go to 3
No
- Repair the (F342) ASD Relay Output circuit for an open circuit or high resistance.
- Perform the PCM Verification Test.PCM Verification Test
3. (K957) SENSOR GROUND CIRCUIT TEST
1. Turn the ignition off.
2. Using a 12 volt test light connected to 12 volts, check the (K957) Sensor Ground circuit in the Mass Air Flow Sensor 1 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
- Go to 4
No
- Go to 9
4. (F342) ASD RELAY OUTPUT CIRCUIT SHORTED TO THE (K157) MAF 1 SIGNAL CIRCUIT
1. Turn the ignition off.
2. Disconnect the Powertrain Control Module (PCM) connector.
3. Measure the resistance between the (F342) ASD Relay Output circuit and the (K157) MAF 1 Signal circuit in the Mass Air Flow Sensor 1 harness connector.
Is the resistance above 100 ohms?
Yes
- Go to 5
No
- Repair the (F342) ASD Relay Output circuit for a short to the (K157) MAF 1 Signal circuit.
- Perform the PCM Verification Test.PCM Verification Test
5. (K157) MAF 1 SIGNAL CIRCUIT SHORTED TO VOLTAGE
1. Turn the ignition on.
2. Measure the voltage of the (K157) MAF 1 Signal circuit in the Mass Air Flow Sensor 1 harness connector.
Is there any voltage present?
Yes
- Repair the (K157) MAF 1 Signal circuit for a short to voltage.
- Perform the PCM Verification Test.PCM Verification Test.
No
- Go to 6
6. (K157) MAF 1 SIGNAL CIRCUIT SHORTED TO GROUND
1. Turn the ignition off.
2. Measure the resistance between ground and the (K157) MAF 1 Signal circuit in the Mass Air Flow Sensor 1 harness connector.
Is the resistance above 100 ohms?
Yes
- Go to 7
No
- Repair the (K157) MAF 1 Signal circuit for a short to ground.
- Perform the PCM Verification Test.PCM Verification Test
7. (K157) MAF 1 SIGNAL CIRCUIT SHORTED TO (K957) SENSOR GROUND CIRCUIT
1. Measure the resistance between the (K157) MAF 1 Signal circuit and the (K957) Sensor Ground circuit in the Mass Air Flow Sensor 1 harness connector.
Is the resistance above 100 ohms?
Yes
- Go to 8
No
- Repair the (K157) MAF 1 Signal circuit for a short to the (K957) Sensor Ground circuit.
- Perform the PCM Verification Test.PCM Verification Test
8. (K157) MAF 1 SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (K157) MAF 1 Signal circuit between the Mass Air Flow Sensor 1 harness connector and the Powertrain Control Module (PCM) harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go to 10
No
- Repair the (K157) MAF 1 Signal circuit for an open circuit or high resistance.
- Perform the PCM Verification Test.PCM Verification Test
9. (K957) SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Powertrain Control Module (PCM) connector.
3. Measure the resistance of the (K957) Sensor Ground circuit between the Mass Air Flow Sensor 1 harness connector and the Powertrain Control Module (PCM) harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go to 11
No
- Repair the (K957) Sensor Ground circuit for an open circuit or high resistance.
- Perform the PCM Verification Test.PCM Verification Test
10. MASS AIR FLOW SENSOR 1
1. Turn the ignition off.
2. Connect the Powertrain Control Module (PCM) connector.
3. Replace the Mass Air Flow Sensor 1.
4. Start the engine and allow it to reach operating temperature.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose fitting clothing. Failure to follow these instructions can result in personal or fatal injury.
NOTE: Review Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set.
5. With a scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go to 11
No
- Test Complete.
- Perform the PCM Verification Test.PCM Verification Test
11. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Mass Air Flow Sensor 1 and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for a DTC to set during the wiggle test.
6. Search for any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the PCM Verification Test.PCM Verification Test
No
- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM Verification Test.PCM Verification Test