Circuit/System Testing
- Ignition OFF, and the MAIN fuse removed, disconnect the harness connector at the throttle body assembly.
- Test for less than 5 ohms of resistance between the ground circuit terminal 1 and ground.
- If greater than the specified range, repair the ground circuit for an open/high resistance.
- Install the MAIN fuse. Ignition ON, test for battery voltage between the battery voltage circuit terminal 2 and ground.
- If less than the specified range, repair the B+ circuit for an open/high resistance.
- Connect a test lamp between the throttle blade control circuit terminal 3 and B+.
- Command the throttle blade from 0-95 percent with a scan tool. The test lamp should respond to the scan tool commands.
- If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.
- If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
- If all circuits test normal, replace the throttle body assembly.