Harness Inspection
- Measure CPS power supply voltage. Disconnect sensor harness connector. Turn ignition on. Using DVOM, measure voltage between sensor harness connector terminal No. 4 (Red wire) and vehicle ground. If voltage is less than battery voltage, inspect and repair circuit as needed.
- Check continuity of ground circuit. Turn ignition off. Using ohmmeter, check resistance between harness connector No. 1 (Black wire) and vehicle ground. If continuity does not exist, inspect and repair circuit as needed.
- Check output voltage from ECM. Turn ignition on. Using DVOM, measure voltage between harness connector terminal No. 2 (Yellow wire) and vehicle ground. Voltage should be 4.8-5.2 volts. If voltage is within specification, circuit is okay. If voltage is not within specification, go to step 4.
- Turn ignition off. Disconnect ECM harness connector. Connect jumper wire between ECM harness connector terminal No. 16 (Green wire) 24-pin connector (Except California), and terminal No. 15 (Green wire) 22-pin connector (California) and vehicle ground. See Figure and Figure . Using ohmmeter, check resistance between CPS harness connector terminal No. 2 (Yellow wire) and vehicle ground. If continuity does not exist, inspect and repair circuit as needed. If continuity exists, substitute ECM with known good unit and retest.