Circuit/System Testing
- Inspect for the following conditions:
- Vacuum hoses for splits, kinks, and proper connections as shown on Vehicle Emission Control Information label
- Inspect thoroughly for any type of leak or restriction
- Air leaks at throttle body mounting area and intake manifold sealing surfaces
- Throttle body for dirt, debris, and coking-Refer to Throttle Body Cleaning .
- Allow the engine to reach operating temperature. Observe the MAP Sensor Voltage parameter with a scan tool. Voltage should be more than 0.8 volt and less than 4 volts.
- If more than 4 volts or less than 0.8 volt, refer to DTC P0106 .
- Idle the engine. Observe the MAP Sensor kPa parameter with a scan tool. Increase the engine speed slowly and then back to idle. The MAP sensor kPa should change smoothly and gradually as engine speed is increased and returned to idle.
- If the MAP sensor kPa does not change, refer to DTC P0106 .
- Take a snapshot of the engine data list while performing the actions listed below. The mass air flow (MAF) sensor g/s should change smoothly and gradually as the engine speed is increased and is returned to idle.
- Idle the engine.
- Increase the engine speed slowly to 3,000 RPM, then back to idle.
- Exit from the snapshot and review the data.
- Observe the Mass Air Flow (MAF) Sensor parameter frame by frame with a scan tool. The MAF sensor g/s should change smoothly and gradually as the engine speed is increased and is returned to idle.
- If the MAF sensor g/s does not change smoothly and gradually as the engine speed is increased and is returned to idle, refer to DTC P0101 or P1101 .
- Inspect the throttle body for the following conditions:
- Loose or damaged throttle blade
- Broken throttle shaft
- Any throttle body damage
- If any of these conditions exist, replace the throttle body assembly.