Circuit/System Testing
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Turn OFF the ignition before inserting fingers into the throttle bore. Unexpected movement of the throttle blade could cause personal injury.
- Inspect the throttle body for the following conditions:
- A throttle blade that is NOT in the rest position
- A throttle valve that is binding open or closed
- A throttle valve that is free to move open or closed WITHOUT spring pressure
- Ignition OFF, disconnect the harness connector at the throttle body.
- Ignition ON, test for 0 volts between each motor control circuit terminal E and F and ground.
- If greater than 0 volts, test the affected motor control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- Ignition ON, verify that a test lamp does not illuminate between each motor control circuit terminal E and F and B+.
- If test lamp illuminates, test the affected motor control circuit for a short to ground. If the circuit tests normal, replace the ECM.
- Ignition OFF, allow sufficient time for the ECM to completely power down. Connect a DMM between the motor control 1 circuit terminal E and ground.
- Using the peak min max function measure for ignition voltage on the motor control 1 circuit as the ignition is turned ON.
- If voltage is not within 1 volt of ignition voltage, test for an open or high resistance. If the circuit tests normal, replace the ECM.
- Ignition OFF, allow sufficient time for the ECM to completely power down. Connect a DMM between the motor control 2 terminal F circuit and ground.
- Using the peak min max function, measure the voltage on the motor control 2 circuit as the ignition is turned ON. Voltage should be within 1 volt of ignition voltage.
- If voltage is not within 1 volt of ignition voltage, test for an open or high resistance. If the circuit tests normal, replace the ECM.
- If all circuits test normal, replace the throttle body.
IMPORTANT:
Disconnecting the throttle body harness connector causes additional DTCs to set.