Camshaft Position Sensor Hall Effect (TBI Federal)
- A malfunction in the camshaft position sensor circuit will set diagnostic trouble Code 42. For testing procedures, see TESTS W/CODES article in this section. Use the following procedure to diagnose camshaft position sensor.
- Ensure ignition is off. Disconnect ECM 24-pin electrical connector C2 (Yellow). ECM is located behind left side of dash. Remove distributor cap from distributor. Remove rotor and signal rotor cover from distributor housing.
- Using voltmeter, probe ECM 17-pin electrical connector C1 (Green - still connected) terminal No. 1 to ECM 24-pin electrical connector C2 (Yellow See Fig 1 . Turn ignition on. Ensure Camshaft Position (CMP) sensor magnet is free from any metal particles.
- CMP sensor voltage with signal rotor inserted between hall element and magnet (magnetic flux cut off) should fluctuate between 0-1 volt. See Figure . If voltage is as specified, go to next step. If voltage is not as specified, check for faulty wiring and ECM. If wiring and ECM are okay, replace distributor housing.
- CMP sensor voltage without signal rotor inserted between hall element and magnet (magnetic flux applied) should indicate battery voltage. See Figure . If voltage is as specified, CMP sensor is okay. Turn ignition off and reverse disassembly procedure.
- If voltage is not as specified, check for faulty wiring and ECM. If wiring and ECM are okay, replace distributor housing. When testing is complete, reverse disassembly procedure.