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Home >> Cadillac >> 2000 >> Seville SLS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Self-Diagnostics - 4.6L >> Diagnostic Tests >> DTC P0102: MAF Sensor Circuit Low Frequency >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing OBD system check, go to next step.
  2. Start engine. Operate engine at idle. Using scan tool, monitor MAF FREQUENCY display. If frequency display is less than 1135 Hz (1.1 kHz), go to step  4. If frequency display is not less than 1135 Hz (1.1 kHz), go to next step.
  3. Turn ignition on, with engine off. Using scan tool, review and record FAIL RECORDS data. Operate vehicle within the fail records conditions. Monitor SPECIFIC DTC INFO for this DTC until test runs. If scan tool indicates that this DTC failed this ignition, go to next step. If scan tool does not indicate that this DTC failed this ignition, see DIAGNOSTIC AIDS .
  4. Turn ignition off. Disconnect MAF sensor harness connector. Turn ignition on, with engine off. Using a DVOM, check voltage between chassis ground and MAF sensor signal circuit. If voltage reading is 4-6 volts, go to next step. If voltage reading is not 4-6 volts, go to step  7.
  5. Check voltage chassis ground and MAF sensor battery feed circuit. If voltage reading is greater than 10 volts, go to next step. If voltage reading is not greater than 10 volts, go to step  8.
  6. Check voltage between MAF sensor harness connector ground and battery feed circuit. If voltage reading is greater than 10 volts, go to step  10. If voltage reading is not greater than 10 volts, go to step  9.
  7. Check MAF sensor signal circuit for open, short to ground or short to voltage. Repair as necessary. After repairs, go to step  14. If circuit is okay, go to step  12.
  8. Repair open or short to ground in MAF sensor battery feed circuit. After repairs, go to step  14.
  9. Repair open or high resistance in MAF sensor ground circuit. After repairs, go to step  14.
  10. Check for poor connections at MAF sensor connector. Repair as necessary. After repairs, go to step  14. If circuit is okay, go to next step.
  11. Replace MAF sensor. After replacing sensor, go to step  14.
  12. Check for poor connection at PCM. Repair as necessary. After repairs, go to step  14. If connections are okay, go to next step.
  13. Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
  14. Using scan tool, review and record FAIL RECORDS data. Clear DTCs. Operate vehicle within fail records conditions. Monitor SPECIFIC DTC INFO for this DTC until test runs. If scan tool indicates that this DTC failed this ignition, repeat step  2. If scan tool does not indicate that this DTC failed this ignition, system is okay.
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