Circuit/System Testing
WARNING: This page is about a different car, the 2006 Saturn Ion 3. However, it is still accessible from the selected car via links, so may be relevant.
- With the ignition OFF, disconnect the harness connector at the CKP sensor.
- With the ignition ON, measure for 4.8-5.2 volts, between the 5-volt reference circuit of the CKP sensor and ground.
- If the voltage is less than 4.8 volts, test for a short to ground, open/high resistance at the circuit, or faulty ECM.
- With the ignition ON, measure for 4.8-5.2 volts between the 5-volt reference circuit of the CKP sensor and the low reference circuit of the CKP sensor.
- If the voltage is less than 4.8 volts, test for an open/high resistance at the circuit or a faulty ECM.
- With the ignition ON, momentarily connect a test lamp between the CKP sensor signal circuit and the 5-volt reference circuit of the CKP sensor. The fuel pump should operate when the test lamp is applied to the CKP sensor signal circuit.
- If the fuel pump does not operate when the test lamp is applied to the CKP sensor signal circuit, test for a short to ground, open/high resistance, short to voltage at the circuit, or a faulty ECM.
- Remove the CKP sensor.
- Inspect the CKP sensor for the following conditions:
- Physical damage
- Excessive play or looseness
- Improper installation
- Foreign material passing between the CKP sensor and the reluctor wheel
- Electromagnetic interference in the CKP sensor circuits
- Inspect the CKP reluctor wheel for the following conditions:
- Physical damage
- Excessive end play or looseness
- Improper installation
- If all circuits and components test normal, replace the CKP sensor.