LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Buick >> 1996 >> Roadmaster Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control Systems - Tests W/Codes >> Diagnostic Trouble Codes >> DTC P0106 - Map System Performance >> Diagnostic Procedures
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) System Check. After performing OBD system check, go to next step.
  2. If DTC P0300 is also present, diagnose DTC. If DTC P0300 is not present, go to next step.
  3. Start and idle engine. Using scan tool, select MAP from ENGINE 1 DATA LIST. If MAP sensor reading is varying more than 6.3 kPa, go to next step. If MAP sensor reading is not varying more than specification, go to step 9).
  4. Turn ignition on, with engine off. Wiggle MAP and PCM sensor harness connectors. Check if MAP value is affected by wiggling the harness connectors. If MAP value is being affected, go to step 12). If MAP value is not being affected, go to next step.
    NOTE: MAP value decreases by about 100 kPa for every 1000 feet of altitude.
  5. Using scan tool, select MAP from ENGINE 1 DATA LIST function. If MAP value is 100 kPa (sea level), go to next step. If MAP value is not 100 kPa, go to step 13).
  6. Remove MAP sensor from intake manifold, leaving harness connector connected. Install a hand-held vacuum pump to MAP sensor. Observe MAP sensor reading on scan tool while applying vacuum. Each one in. Hg. applied should result in 3-4 kPa drop. Value should change smoothly with each increase in vacuum. If MAP value changed smoothly without any erratic reading, go to step 13). If reading was erratic, go to next step.
  7. Apply up to 20 in. Hg. to MAP sensor. If MAP sensor reads 34 kPa or less, go to next step. If not, go to step 13).
  8. Remove vacuum source from MAP sensor. If MAP sensor reading returns to original value, go to next step. If reading does not return to original value, go to step 13).
  9. 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 P0106. If scan tool indicates that this test failed this ignition, go to next step. If scan tool does not indicate that this test failed this ignition, see DIAGNOSTIC AIDS.
  10. Check MAF sensor harness for incorrect routing near secondary ignition or components, solenoids, relays, or motors. Repair as necessary. After repairs, go to step 16). If routing is okay, go to next step.
  11. Check for plugged or leaking vacuum supply to MAP sensor. Repair as necessary. After repairs, go to step 13). If vacuum supply to MAP sensor is okay, go to step 14).
  12. Check for poor terminals connections. Check for rubbed-through wire insulation, broken wire inside insulation or misrouted harness. Repair as necessary. After repairs, go to step 16). If circuits are okay, go to next step.
  13. Replace MAP sensor. After replacing MAP sensor, go to step 16).
  14. Check connections to PCM. Repair as necessary. After repairs, go to step 16). If connections are okay, go to next step.
  15. Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
  16. Using scan tool, select DTC, CLEAR INFO function. Start and operate engine to normal operating temperature. Select DTC, SPECIFIC then enter DTC number that was set. Operate vehicle within the conditions that set the DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2).
  17. Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are present, diagnose affected DTCs.
scientia non olet · About LEMON Manuals