The 3x Crankshaft Position (CKP) sensor, used on 1994-95 3.1L (VIN M) engines, provides a signal to the PCM through the ignition control module. The PCM uses this signal to determine RPM and crankshaft position.
See Figure 1
The best method to test this sensor is with the use of an oscilloscope.
- Visually check the connector, making sure it is connected properly and all of the terminals are straight, tight and free of corrosion.
- With the ignition in the ON position, check the sensor voltage using an oscilloscope. When the starter is briefly operated, a sine wave pattern, alternating from high voltage to low voltage should be seen. If the voltage is less than 0.1 volt the sensor is faulty.
- If the voltage is within specification, check the resistance at the CKP terminals. If the resistance is not between 900-1200 ohms, the sensor is faulty.
- If the signal and resistance of the CKP sensor are within specifications, use a DVOM to check for continuity (short, open or high resistance greater than 0.50 ohms) in the CKP circuit wires and repair as necessary.
- If the sensor and circuits are functional, the computer control module may be faulty.
REMOVAL & INSTALLATION
3.1L (VIN M) Engine
See Figure 2
- Turn the steering wheel all the way to the left.
- Be sure the ignition is in the OFF or LOCK position, then disconnect the negative battery cable.
- Raise and safely support the vehicle.
- Disengage the wiring harness connector from the sensor.
- Remove the sensor retaining bolt, then carefully remove the sensor from the lower right side of the engine block.
- Inspect the sensor O-ring and replace, if necessary.
- Lubricate the O-ring with clean engine oil, then install the sensor into the hole in the side of the engine block.
- Install the sensor retaining bolt and tighten to 71 inch lbs. (8 Nm).
- Engage the sensor wiring harness at the module.
- Carefully lower the vehicle, then connect the negative battery cable.
- Turn the steering wheel back to its original position.