LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Pontiac >> 2003 >> Aztek AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics >> Diagnostic Tests >> DTC P0102: MAF Sensor Circuit - Low Frequency >> Diagnostic Procedures
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Procedures

  1. Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, see DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM.
  2. Start engine. Observe the MAF sensor frequency with a scan tool. Is the MAF sensor frequency less than 1200 Hz? If yes, go to step  4. If no, go to next step.
  3. Observe the Freeze Frame/Failure Records data for this DTC. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running DTC or as close to the Freeze Frame/Failure Records data that you observed. Does the DTC fail this ignition cycle? If yes, go to next step. If no, see DIAGNOSTIC AIDS .
  4. Observe the MAF sensor frequency with a scan tool. Move the harness and the connector of the MAF sensor. Does the movement of the harness or the connector affect the MAF sensor frequency? If yes, go to step  19. If no, go to next step.
  5. Turn ignition off. Inspect for the following conditions:
    • A restricted or collapsed air intake duct.
    • A dirty or deteriorating air filter element.
    • Any objects blocking the air inlet screen of the MAF sensor.
    • Any debris on the sensing elements of the MAF sensor.
    • A restricted exhaust system.
    • Any vacuum leak downstream of the MAF sensor.
    • A MAF sensor that is installed backwards.

    Did you find and correct the condition? If yes, go to step  27. If no, go to next step.

  6. Inspect the fuse in the ignition 1 voltage circuit of the MAF sensor. Is the fuse open? If yes, go to step  13. If no, go to next step.
  7. Turn ignition on, with engine off. Disconnect the MAF/IAT sensor. Connect a test light between the ignition 1 voltage circuit of the MAF sensor and a good ground. Connect the DVOM to the probe of the test light and a good ground. Is the voltage less than battery voltage? If yes, go to step  20. If no, go to next step.
    8. NOTE: All electrical components and accessories must be turned OFF.
  8. Turn ignition off for 60 seconds to allow the control modules to power down. Measure the resistance from the ground circuit of the MAF sensor to a good ground with a DVOM. Is the resistance less than 5 ohms? If yes, go to next step. If no, go to step  21.
  9. Turn ignition on, with engine off. Measure the voltage from the signal circuit of the MAF sensor to a good ground with a DVOM. Is voltage within 4.8-5.2 volts? If yes, go to next step. If no, go to step  12.
  10. Connect a 3-amp fused jumper wire between the signal circuit of the MAF sensor and a good ground. Start engine. Observe the DTC Information with a scan tool. Do any additional DTCs set? If yes, go to step  23. If no, go to next step.
    11. NOTE: An abnormal resistance on the signal circuit will disable the MAF sensor frequency before the voltage starts to drop out of the correct parameter of 4.8-5.2 volts.
  11. Test the MAF sensor signal circuit for a high resistance. Did you find and correct the condition? If yes, go to step  27. If no, go to step  17.
  12. Is the voltage less than 4.8 volts? If yes, go to step  14. If no, go to step  15.
    13. NOTE: The ignition 1 voltage circuit of the MAF sensor is spliced to other components of the vehicle.
  13. Test the ignition 1 voltage circuit for a short to ground. Did you find and correct the condition? If yes, go to step  27. If no, go to next step.
  14. Turn ignition off. Disconnect the PCM. Test the signal circuit between the PCM and the MAF sensor for a high resistance, open circuit, or a short to ground. Did you find and correct the condition? If yes, go to step  27. If no, go to step  16.
    15. NOTE: Disconnecting the PCM connectors may eliminate the short to voltage if the signal circuit is shorted to another PCM circuit.
  15. Turn ignition off. Disconnect PCM. Turn ignition on, with engine off. Measure the voltage from the signal circuit of the MAF sensor to a good ground with a DVOM. Is the voltage more than zero volts? If yes, go to step  22. If no, go to next step.
  16. Measure the resistance from the signal circuit of the MAF sensor to all other circuits at both PCM connectors with a DVOM. Is resistance less than 8 ohms? If yes, go to step  24. If no, go to step  18.
  17. 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  27. If no, go to step  25.
  18. Test for an intermittent and for a poor connection at the PCM. Did you find and correct the condition? If yes, go to step  27. If no, go to step  26.
  19. Repair wiring or the connector as needed. After repairs, go to step  27.
  20. Repair high resistance or open in the MAF sensor ignition 1 voltage circuit. After repairs, go to step  27.
  21. Repair high resistance or open in the MAF sensor ground circuit. After repairs, go to step  27.
  22. Repair short to voltage in the MAF sensor signal circuit. After repairs, go to step  27.
  23. Repair short between the MAF sensor signal circuit and the 5-volt reference circuit for which the DTC set. After repairs, go to step  27.
  24. Repair circuits that are shorted together. After repairs, go to step  27.
  25. Replace MAF sensor. See REMOVAL & INSTALLATION - AZTEC & RENDEZVOUS article. After replacing sensor, go to step  27.
  26. Replace PCM. See REMOVAL & INSTALLATION - AZTEC & RENDEZVOUS article. Reprogram PCM. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After repairs, go to next step.
  27. Clear the DTCs with a scan tool. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running DTC. See CONDITIONS FOR RUNNING DTC . Does the DTC run and pass? If yes, go to next step. If no, go to step  2.
  28. Observe the stored information, Capture Info with a scan tool. Does the scan tool display any DTCs that you have not diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.
scientia non olet · About LEMON Manuals