Circuit/System Verification
- Ignition ON, verify that DTC P0641 or P0651 is not set.
- If any of the DTCs are set
Refer to DTC P0641 or P0651 (ECM) for further diagnosis.
- If the none of the DTCs are set
- If any of the DTCs are set
- If you were sent here from DTC P0068, P0106, P0121, or P1101 refer to Circuit/System Testing (below).
- Ignition ON, verify the scan tool Throttle Body Idle Air Flow Compensation parameter is less than 90 %..
- 90 % or greater
Refer to Throttle Body Cleaning .
- If less than 90 %
- 90 % or greater
- Verify the scan tool Throttle Position Sensors 1 and 2 Agree/Disagree parameter displays Agree while performing the Throttle Sweep Test with a scan tool.
- If Disagree
Refer to DTC P0120-P0123, P0220, P0222, P0223, or P2135 for further diagnosis.
- If Agree
- If Disagree
- Determine the current vehicle testing altitude.
- Verify the scan tool MAP Sensor pressure parameter is within the range specified in the Altitude Versus Barometric Pressure
table.
- The MAP Sensor pressure is not in range
Refer to DTC P0106 for further diagnosis.
- The MAP Sensor pressure is within range
- The MAP Sensor pressure is not in range
- Engine idling, verify the scan tool MAP Sensor pressure parameter is between 26-52 kPa (3.8-7.5 PSI) and changes with accelerator pedal input.
- If not between 26-52 kPa (3.8-7.5 PSI) or does not change
Refer to DTC P0106 for further diagnosis.
- If between 26-52 kPa (3.8-7.5 PSI) and changes
- If not between 26-52 kPa (3.8-7.5 PSI) or does not change
- Verify the scan tool MAF Sensor g/s parameter changes smoothly and gradually as the engine speed is increased and decreased while performing the actions listed below.
- Engine idling
- Perform the scan tool snapshot function.
- Increase the engine speed slowly to 3,000 RPM and then back to idle.
- Exit from the scan tool snapshot and review the data.
- Observe the MAF Sensor parameter frame by frame with a scan tool.
- The MAF Sensor parameter does not change smoothly and gradually
Refer to Circuit/System Testing (below).
- The MAF Sensor parameter changes smoothly and gradually
- Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
- Verify the DTC does not set.
- If the DTC sets
Refer to Circuit/System Testing (below).
- If the DTC does not set
- If the DTC sets
- All OK