See Figure 1
The Crankshaft Position (CKP) sensor, located on the front cover (near the crankshaft pulley) is used to determine crankshaft position and crankshaft rpm. The CKP sensor is a reluctance sensor which senses the passing of teeth on a sensor ring because the teeth disrupt the magnetic field of the sensor. This disruption creates a voltage fluctuation, which is monitored by the PCM.
See Figures 2 and 3
Using a DVOM set to the DC scale to monitor less than 5 volts, measure the voltage between the sensor Cylinder Identification (CID) terminal and ground by backprobing the sensor connector. If the connector cannot be backprobed, fabricate or purchase a test harness. The sensor is okay if the voltage reading varies more than 0.1 volt with the engine running at varying RPM.
REMOVAL & INSTALLATION
See Figures 4, 5, 6 and 7
- Disconnect the negative battery cable.
- Disengage the wiring harness connector from the CKP sensor.
- Loosen the CKP sensor mounting stud/bolts, then separate the sensor form the engine front cover.
When installing a new sensor on the 4.0L, position the sensor against the crankshaft damper. There are small rub tabs which wear off and allow the sensor to be perfectly spaced from the damper.
- Position the sensor against the engine front cover, then install the mounting stud/bolts. Tighten them until snug.
- Install the CKP sensor cover and retaining nuts; tighten the nuts until snug.
- Reattach the wiring harness connector to the CKP sensor.
- Connect the negative battery cable.