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Home >> Chevrolet >> 2001 >> Venture Base, Van Passenger >> Repair and Diagnosis >> External Pages >> Different car >> Section 213 (Engine Controls - Self-Diagnostics - 3.0L) >> Diagnostic Tests >> DTC P0103: Mass Airflow Sensor Circuit - High Signal/Frequency >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
  1. Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS .
    2. NOTE: If you were sent here from P0101, proceed to next step.
  2. Observe the Freeze Frame/Failure Records for this DTC. Turn ignition off for 90 seconds. Start engine. Operate vehicle within the Conditions for Running the DTC. See CONDITIONS FOR RUNNING DTC  or as close to the Freeze Frame/Failure Records that you observed. Does the DTC fail this ignition? If yes, go to next step. If no, go to DIAGNOSTIC AIDS .
  3. Idle the engine. Observe the MAF sensor voltage with a scan tool. Is the MAF sensor voltage more than 4.8 volts? If yes, go to step  5. If no, go to next step.
  4. Turn ignition off. Inspect for a dirty air filter element, deteriorating air filter element, debris on the air diffuser of the MAF sensor, debris or contamination on the sensing element of the MAF sensor, or any water in the air induction system. Did you find and correct the condition? If yes, go to step  17. If no, go to next step.
  5. Ensure the engine remains idling. Disconnect the MAF sensor harness connector. Observe the MAF sensor voltage with a scan tool. Is the voltage more than zero volts? If yes, go to step  10. If no, go to next step.
  6. Turn ignition off. Turn ignition on, with engine off. Probe the low reference circuit of the MAF sensor with a test light that is connected to a good ground. Does the test light illuminate? If yes, go to step  12. If no, go to next step.
    7. NOTE: Verify that the ECM has shut down prior to measuring the resistance of the low reference circuit of the MAF sensor. This can be verified by the loss of communication on the scan tool.
  7. Turn ignition off for 90 seconds. Turn OFF all accessories and electrical components. Measure the resistance from the low reference circuit of the MAF sensor to a good ground with a DVOM. Is the resistance less than 5 ohms? If yes, go to step  13. If no, go to next step.
  8. Disconnect the ECM harness connector. Test the low reference circuit of the MAF sensor for a high resistance or an open circuit. Did you find and correct the condition? If yes, go to step  17. If no, go to next step.
  9. Measure the resistance from the ECM case to a good ground with a DVOM. Is the resistance less than 5 ohms? If yes, go to step  14. If no, go to step  11.
    10. NOTE: Disconnecting the ECM connectors may eliminate the short to voltage if the signal circuit is shorted to another ECM circuit.
  10. Turn ignition off. Disconnect the ECM. Test the signal circuit of the MAF sensor for a short to the 5-volt reference, circuit "A" shorted to the 5-volt reference "B", circuit "A" shorted to the 5-volt reference "C", or circuit "A" shorted to voltage. Did you find and correct the condition? If yes, go to step  17. If no, go to step  14.
  11. Repair the high resistance or an open in the ground circuit of the ECM. After repairs, go to step  17.
    12. NOTE: A short to voltage on the low reference circuit of the MAF sensor may cause internal damage to the ECM. Verify proper system operation after completing the repair.
  12. Repair the short to voltage in the low reference circuit of the MAF sensor. After repairs, go to step  17.
  13. Test for an intermittent and for a poor connection at the MAF sensor. Did you find and correct the condition? If yes, go to step  17. If no, go to step  15.
  14. Test for an intermittent and for a poor connection at the ECM. Did you find and correct the condition? If yes, go to step  17. If no, go to step  16.
  15. Replace MAF/IAT sensor. After replacing sensor, go to step  17.
  16. Replace ECM. Perform ECM relearn procedures. See ENGINE CONTROL MODULE  under PROGRAMMING. After replacing ECM, go to next step.
  17. Replace ECM. Perform ECM relearn procedures. See ENGINE CONTROL MODULE  under PROGRAMMING. After replacing ECM, go to next step.
  18. Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? If yes, diagnose affected DTC(s). See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are displayed, system is okay.
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