DTC P0340: Camshaft Position (CMP) Sensor Circuit Malfunction
- Remove PCM, leaving wiring harnesses connected. Remove distributor cap and rotor. Turn ignition on. If equipped with 3-speed automatic or manual transmission, go to next step. If equipped with 4-speed automatic transmission, go to step 3).
- Using DVOM, measure voltage (backprobe) between ground and terminal No. 3 (White wire) at 26-pin PCM harness connector while rotating distributor shaft. As Hall Effect signal rotor breaks magnetic field of CMP sensor, voltage should be 3-5.25 volts. As Hall Effect signal rotor passes CMP sensor, voltage should return to 0-1 volt. If voltage is as specified, replace PCM and retest system. If voltage is a constant 3-5.25 volts, go to step 4). If voltage is a constant 0-1 volt, go to step 5).
- Using DVOM, measure voltage (backprobe) between ground and terminal No. 3 (White wire) at 22-pin PCM harness connector while rotating distributor shaft. As Hall Effect signal rotor breaks magnetic field of CMP sensor, voltage should be 3-5.25 volts. As Hall Effect signal rotor passes CMP sensor, voltage should return to 0-1 volt. If voltage is as specified, replace PCM and retest system. If voltage is a constant 3-5.25 volts, go to next step. If voltage is a constant 0-1 volt, go to step 5).
- Check for an open in Blue/Black wire or Black/Blue wire (changes to Black/Orange wire on some models) from CMP sensor. Repair as necessary. If wires are okay, replace CMP sensor and retest system.
- Check for poor harness connections at PCM. Check for a short to ground in White wire between CMP sensor and PCM. Repair as necessary. If wire is okay, replace CMP sensor and retest system.