2000 - 2999: 2068
2068-MASS AIR FLOW SENSOR SHORT/OPEN CIRCUIT
For a complete wiring diagram Consult Diagrams/Electrical
- When Monitored:
With the engine running, battery voltage greater than 10 volts and no related DTCs present.
- Set Condition:
The PCM detects that the input voltage is not within a specified range based on operating conditions.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.Initial Inspection and Diagnostic Overview
Diagnostic Test
1. DTC IS ACTIVE
Turn the ignition on.
With the scan tool, read DTCs.
Record all DTC and applicable Freeze Frame information.
NOTE: Diagnose and repair any Intake Air Temperature sensor DTCs before proceeding with this test.
With the scan tool, clear DTCs.
Cycle the ignition off for at least one minute.
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.
With the scan tool, read DTCs.
Does this DTC reset?
Yes
- Go to 2
No
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.Checking for an Intermittent DTC
2. INTAKE AIR SYSTEM LEAKING OR RESTRICTED
Inspect the air cleaner housing and related hoses/tubes and connections for leaks or obstructions.
Remove and inspect the Air Filter for soiling or excessive dirt and debris which may cause air flow restriction.
Inspect the connections between the air cleaner housing and the Mass Air Flow Sensor and between the Mass Air Flow Sensor and the Throttle Body.
Were any problems found?
Yes
- Repair as necessary and retest.
- Perform the PCM Verification Test.Powertrain Verification Test
No
- Go to 3
3. FUSED MAIN RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE
Turn the ignition off.
Disconnect the Mass Air Flow Sensor connector.
Turn the ignition on.
Using a 12 volt test light connected to ground, check the 5 Volt Supply 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
- Go to 4
No
- Repair the 5 Volt Supply circuit for an open circuit or high resistance.
- Perform the PCM Verification Test.Powertrain Verification Test
4. SENSOR GROUND CIRCUIT TEST
Turn the ignition off.
Using a 12 volt test light connected to 12 volts, check the Sensor Ground 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
- Go to 5
No
- Go to 14
5. 5 VOLT SUPPLY CIRCUIT SHORTED TO THE MAF SIGNAL CIRCUIT
Turn the ignition off.
Disconnect the Powertrain Control Module (PCM) connector.
Measure the resistance between the 5 Volt Supply circuit and the MAF Signal circuit in the Mass Air Flow Sensor harness connector.
Is the resistance above 100 ohms?
Yes
- Go to 6
No
- Repair the 5 Volt Supply circuit for a short to the MAF Signal circuit.
- Perform the PCM Verification Test.Powertrain Verification Test
6. 5 VOLT SUPPLY CIRCUIT SHORTED TO THE SENSOR GROUND CIRCUIT
Measure the resistance between the 5 Volt Supply circuit and the Sensor Ground circuit in the Mass Air Flow Sensor harness connector.
Is the resistance above 100 ohms?
Yes
- Go to 7
No
- Repair the 5 Volt Supply circuit for a short to the Sensor Ground circuit.
- Perform the PCM Verification Test.Powertrain Verification Test
7. 5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE
Turn the ignition on.
Measure the voltage of the 5 Volt Supply circuit in the Mass Air Flow Sensor harness connector.
Is there any voltage present?
Yes
- Repair the 5 Volt Supply circuit for a short to voltage.
- Perform the PCM Verification Test.Powertrain Verification Test.
No
- Go to 8
8. 5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Measure the resistance between ground and the 5 Volt Supply circuit in the Mass Air Flow Sensor harness connector.
Is the resistance above 100 ohms?
Yes
- Go to 9
No
- Repair the 5 Volt Supply circuit for a short to ground.
- Perform the PCM Verification Test.Powertrain Verification Test
9. 5 VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE
Measure the resistance of the 5 Volt Supply circuit between the Mass Air Flow Sensor harness connector and the Powertrain Control Module (PCM) harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go to 10
No
- Repair the 5 Volt Supply circuit for an open circuit or high resistance.
- Perform the PCM Verification Test.Powertrain Verification Test
10. MAF SIGNAL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition on.
Measure the voltage of the MAF Signal circuit in the Mass Air Flow Sensor harness connector.
Is there any voltage present?
Yes
- Repair the MAF Signal circuit for a short to voltage.
- Perform the PCM Verification Test.Powertrain Verification Test.
No
- Go to 11
11. MAF SIGNAL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Measure the resistance between ground and the MAF Signal circuit in the Mass Air Flow Sensor harness connector.
Is the resistance above 100 ohms?
Yes
- Go to 12
No
- Repair the MAF Signal circuit for a short to ground.
- Perform the PCM Verification Test.Powertrain Verification Test
12. MAF SIGNAL CIRCUIT SHORTED TO SENSOR GROUND CIRCUIT
Measure the resistance between the MAF Signal circuit and the Sensor Ground circuit in the Mass Air Flow Sensor harness connector.
Is the resistance above 100 ohms?
Yes
- Go to 13
No
- Repair the MAF Signal circuit for a short to the Sensor Ground circuit.
- Perform the PCM Verification Test.Powertrain Verification Test
13. MAF SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
Measure the resistance of the MAF Signal circuit between the Mass Air Flow Sensor harness connector and the Powertrain Control Module (PCM) harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go to 15
No
- Repair the MAF Signal circuit for an open circuit or high resistance.
- Perform the PCM Verification Test.Powertrain Verification Test
14. SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE
Turn the ignition off.
Disconnect the Powertrain Control Module (PCM) connector.
Measure the resistance of the Sensor Ground circuit between the Mass Air Flow Sensor harness connector and the Powertrain Control Module (PCM) harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go to 16
No
- Repair the Sensor Ground circuit for an open circuit or high resistance.
- Perform the PCM Verification Test.Powertrain Verification Test
15. MASS AIR FLOW SENSOR
Turn the ignition off.
Connect the Powertrain Control Module (PCM) connector.
Replace the Mass Air Flow Sensor.
Turn the ignition on.
With the scan tool, clear DTCs.
Cycle the ignition off for at least one minute.
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.
With a scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go to 16
No
- Test Complete.
- Perform the PCM Verification Test.Powertrain Verification Test
16. POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Mass Air Flow Sensor and the Powertrain Control Module (PCM).
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 a DTC to set during the wiggle test.
Search for any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the PCM Verification Test.Powertrain Verification Test
No
- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM Verification Test.Powertrain Verification Test