Circuit/System Testing
- Ignition OFF, disconnect the harness connector of the CMP sensor.
- Connect a test lamp between the ignition 1 voltage circuit of the CMP sensor and the negative terminal of the battery.
- Ignition ON, test for less than 0.5 volt between the ignition 1 voltage circuit of the CMP sensor and the positive terminal of the battery.
- If greater than 0.5 volt, repair the ignition 1 voltage circuit of the CMP sensor for a short to ground or an open/high resistance.
- Connect a test lamp between the ground circuit and the ignition 1 voltage circuit of the CMP sensor.
- If the test lamp does not illuminate, test for an open/high resistance on the ground circuit. If circuit/connections test normal, replace the ECM.
- Ignition OFF, connect a DMM between the signal circuit and the low reference circuit of the CMP sensor.
- Ignition ON, verify that 4.8-5.2 volts is available on the signal circuit and the low reference circuit of the CMP sensor.
- If less than 4.8 volts, test the signal circuit for a short to ground or an open/high resistance. If the circuits/connections test normal, replace the ECM.
- If more than 5.2 volts, test the signal circuit for a short to voltage. If the circuits/connections test normal, replace the ECM.
- If all circuits/connections test normal, replace the CMP sensor.
IMPORTANT:
The test lamp is used to load the circuit and may not illuminate.