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Home >> Chevrolet >> 2002 >> Impala LS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics - 3.8L >> Diagnostic Tests >> DTC P0101: MAF System Performance >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform Diagnostic System Check - Engine Controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM. After performing Diagnostic System Check - Engine Controls, go to next step.
  2. Install scan tool. Start engine. Monitor DTC information using scan tool. Does the scan tool display any other DTCs? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, go to next step.
  3. Record FREEZE FRAME/FAILURE RECORDS data for this DTC. Turn ignition off for 30 seconds. Start engine. Operate vehicle within Conditions for Running DTC or as close to FREEZE FRAME/FAILURE RECORDS data as possible. Does the DTC fail this ignition cycle? If yes, go to next step. If no, see DIAGNOSTIC AIDS .
  4. Turn off all accessories. Allow engine to idle at normal operating temperature. Using scan tool, observe MAP sensor voltage parameter. Does scan tool indicate MAP sensor is 19-48 kPa? If yes, go to next step. If no, see MANIFOLD ABSOLUTE PRESSURE SENSOR under appropriate SYSTEM & COMPONENT TESTING article.
  5. Idle the engine. Observe MAP sensor kPa with a scan tool. Increase engine speed slowly to 3,000 RPM and then back to idle. Does the MAP sensor kPa change smoothly and gradually through the specified range of the test? If yes, go to next step. If no, see MANIFOLD ABSOLUTE PRESSURE SENSOR under appropriate SYSTEM & COMPONENT TESTING article.
  6. Turn off the ignition. Turn on the ignition, with the engine off. Observe the TP sensor angle from closed throttle to WOT. Depress completely and then release the accelerator pedal. Does the scan tool indicate that the TP sensor angle changed smoothly and completely through 0-100 percent? If yes, go to next step. If no, see DTC P0121: TP SENSOR PERFORMANCE .
  7. Inspect for the following conditions:
    • A restricted air intake duct.
    • A collapsed air intake duct.
    • A dirty air filter element.
    • A 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.
    • Any vacuum leak downstream of the MAF sensor.
    • A poor vacuum connection at the MAP sensor.
    • A restricted exhaust system.

    Did you find and correct the condition? If yes, go to step  10. If no, go to next step.

  8. 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  10. If no, go to next step.
  9. Replace MAF sensor. After repairs, go to step  10.
  10. Using scan tool, clear DTCs. Turn ignition off for 30 seconds. Start engine. Operate vehicle within Conditions for Running DTC. Does DTC run and pass? If yes, go to next step. If no, go to step  2.
  11. Using scan tool, observe stored information. Does scan tool display any DTCs that have not been diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.
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