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Home >> Chevrolet >> 1999 >> Forward Control P12 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Tests W/Codes - DTC P0100-P0134 >> DTC P0101 >> DTC P0101: MAF System Performance (4.6L SEVILLE) >> Diagnostic Procedures
July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
  2. Start engine. Using scan tool, monitor MAF sensor frequency. If value is greater than 1135 Hz, fault is not present. Check for intermittent condition by wiggling wire harnesses. If value is not as specified, go to next step.
  3. Turn ignition off. Disconnect MAF sensor connector. Turn ignition on. Using DVOM, measure voltage between ground and signal circuit at MAF sensor harness connector. If voltage is 4.7-5.3 volts, go to next step. If voltage is not as specified, go to step  6.
  4. Using DVOM, measure voltage between ground and ignition positive feed circuit at MAF sensor harness connector. If voltage is 10.5-15 volts, go to next step. If voltage is not as specified, go to step  7.
  5. Using DVOM, measure voltage between ground circuit and ignition positive feed circuit at MAF sensor harness connector. If voltage measured is within 0.5 volt of voltage measured in step 4)  , go to step  9. If voltage is not as specified, go to step  8.
  6. Turn ignition off. Using scan tool, record FLUID LIFE INDEXES, and then wait 30 seconds. Disconnect PCM harness connector C2 (Clear). Check MAF sensor signal circuit for an open or short to ground. Repair as necessary and retest. If no problem is found, go to step  11.
  7. Repair open or high resistance in MAF sensor ignition positive feed circuit and retest.
  8. Repair open or high resistance in MAF sensor ground circuit and retest.
  9. Check MAF sensor harness connector for poor terminal contact. Repair as necessary and retest. If no problem is found, go to next step.
  10. Replace MAF sensor and retest.
  11. Check PCM harness connector C2 (Clear) for poor terminal contact. Repair as necessary and retest. If no problem is found, go to next step.
  12. Replace PCM. Perform PCM reprogramming procedures.
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