LEMON Manuals: Even more car manuals for everyone
Home >> Buick >> 1996 >> Roadmaster Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control Systems - Tests W/Codes >> Diagnostic Trouble Codes >> DTC P0100 - MAF Sensor Circuit Insufficient Activity >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) System Check. After performing OBD system check, go to next step.
  2. Start and operate engine at idle. Using scan tool, select ENGINE 1 DATA LIST function and monitor MAF GM/S display. If value is less than 3.9 gm/s, go to step 4). If value is 3.9 gm/s or more, go to next step.
  3. Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data and note parameters. Turn ignition off for about 15 seconds. Start engine and operate vehicle within the conditions required for this diagnostic to run, and as close to conditions recorded in FREEZE FRAME/FAILURE RECORDS as possible. Select DTC function, then enter DTC which was set. If scan tool indicates that this test failed this ignition, go to next step. If scan tool did not indicate that this test failed this ignition, see DIAGNOSTIC AIDS.
  4. Turn ignition off. Disconnect MAF sensor harness connector. Turn ignition on, with engine off. Using DVOM, check voltage between MAF signal circuit and battery ground. DVOM should read about 5 volts. If voltage reading is as specified, go to next step. If voltage reading is not as specified, go to step 8).
  5. Connect a test light between MAF sensor ignition feed circuit and ground circuit at MAF sensor harness connector. If test light illuminates, go to step 7). If test light does not illuminate, go to next step.
  6. Connect test light between MAF sensor ignition feed circuit and battery ground. If test light illuminates, go to step 9). If test light does not illuminate, go to step 10).
  7. Check for poor connection at MAF harness terminals. Repair or replace faulty terminal(s). After repairs, go to step 13). If connections were okay, go to step 11).
  8. Disconnect PCM. Check MAF signal circuit between PCM and MAF sensor for open, short to ground, short to MAF sensor ground circuit or short to voltage. Repair as necessary. After repairs, go to step 13). If circuits were okay, go to step 12).
  9. Locate and repair open in ground circuit to MAF sensor. After repairs, go to step 13).
  10. Locate and repair open in ignition feed circuit to MAF sensor. After repairs, go to step 13).
  11. Replace MAF sensor. After repairs, go to step 13).
  12. Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
  13. Clear DTC(s) using scan tool. Start and warm engine to normal operating temperature. Using scan tool, select DTC, SPECIFIC, then enter DTC that was set. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If test did not run or ran and failed, repeat step 2).
  14. Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTC(s) are present, diagnose affected DTC.
scientia non olet · About LEMON Manuals