LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 102 (Engine Controls - Self-Diagnostics - 3.5L) >> Diagnostic Tests >> DTC P0101: Mass Airflow Sensor System Performance >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2002 Oldsmobile Intrigue and 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
  1. Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM.
  2. Start engine. Using scan tool, check for any other DTCs that are set. Does scan tool display any other DTCs set? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, go to next step.
  3. Using scan tool, observe and record FREEZE FRAME/FAILURE RECORDS data for this DTC. Turn ignition off for 30 seconds. Start engine. Operate vehicle within conditions for running the DTC as specified in Conditions For Running DTC or as close to recorded FREEZE FRAME/FAILURE RECORDS data as possible. See CONDITIONS FOR RUNNING DTC . If DTC resets, go to next step. If DTC does not reset, see DIAGNOSTIC AIDS .
  4. Allow engine to reach operating temperature. Observe MAP sensor voltage with a scan tool. Is MAP sensor voltage is within 0.8-4.0 volts? If yes, go to next step. If no, see DTC P0107: MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT LOW VOLTAGE  or DTC P0108: MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT HIGH VOLTAGE  .
  5. Operate engine at idle. Using scan tool, observe MAP sensor kPa. Increase engine speed slowly to 3000 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 DTC P0107: MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT LOW VOLTAGE  or DTC P0108: MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT HIGH VOLTAGE  .
  6. Turn ignition off. Turn ignition on, with engine off. Observe TP sensor angle from closed throttle to Wide Open Throttle (WOT). Completely depress and then release accelerator pedal. Does scan tool indicate that TP sensor angle changed smoothly and completely through the specified range of the test (0-100 percent)? If yes, go to next step. If no, go to DTC P0121: THROTTLE POSITION SENSOR CIRCUIT INSUFFICIENT ACTIVITY .
  7. Check for a restricted air intake duct, collapsed air intake duct, misaligned air intake duct, dirty air filter element, deteriorating air filter element, any objects blocking MAF sensor air inlet screen, debris on sensing elements of MAF sensor, any vacuum leak downstream of MAF sensor, poor vacuum connection at MAP sensor, or 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 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. When complete, go to next step.
  10. Using scan tool, order to clear DTCs. Turn ignition for 30 seconds. Start and operate vehicle within the Conditions for Running the DTC. See CONDITIONS FOR RUNNING DTC . Does the DTC run and pass? If yes, go to next step. If no, go to step  2.
  11. Using scan tool, check for any other DTCs that are set. If no other DTCs are set, system is okay. If any other DTCs are set, repair DTCs as necessary. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .
scientia non olet · About LEMON Manuals