Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the VSS.
- Ignition OFF, test for less than 1 ohm of resistance between the low reference circuit and ground.
- If greater than the specified range, repair the ground circuit for an open/high resistance.
- Ignition ON, verify a test lamp illuminates between the ignition 1 voltage circuit and ground.
- If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition 1 voltage circuit fuse is open, test all components connected to the ignition 1 voltage circuit and replace as necessary.
- Ignition ON, test for 9-11 volts between the signal circuit and ground.
- If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
- If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- If the voltage is within the specified range replace the VSS.