How to Change the Crankshaft Sensor in a Jeep Autoby Dan Ferrell
The computer on your Jeep vehicle uses the crankshaft position (CKP) sensor to monitor crankshaft position and speed. Changing the unit may seem simple at first. After all, it only has one or two bolts or nuts. Still, depending on your particular Jeep model, replacing the unit requires careful attention to details. A wrongly positioned CKP sensor may prevent your vehicle from starting. Moreover, installing it without a spacer will ruin the sensor.
Removing the Crankshaft Sensor
Park your Jeep safely away from traffic.
Open the hood and locate the (CKP) sensor to the left (driver side) of the transmission bell housing, where it meets the rear of the engine block. If necessary, shift the transmission to neutral (N), raise the front of your vehicle using a floor jack and safely support it on two jack stands. Chock the rear wheels.
Locate the CKP sensor pigtail connector to the right (passenger side) of the transmission bell housing. Unplug the CKP electrical connector.
Thoroughly clean the area around the crankshaft sensor using a soft brush and a shop rag.
Note whether the CKP sensor on your Jeep model is mounted with one bolt, two bolts or two nuts. If there is only one bolt, make a note of the exact sensor position, since it is adjustable and you will need to reinstall it in the same position.
Unscrew the sensor mounting bolt(s) or nuts using a ratchet, ratchet extension and socket of the appropriate size. If your Jeep model uses two mounting bolts, use the same bolts during the installation process. These bolts have been machined to provide the correct space between the crankshaft sensor and the flywheel. If you use bolts with a different configuration, your vehicle may not start or operate properly.
Remove the crankshaft sensor from your vehicle.
Installing the Crankshaft Sensor
Thoroughly clean the sensor-mounting surface on the transmission bell housing using a soft brush and a shop rag.
Clean the mounting bolt(s) or nuts using the soft brush and shop rag.
Check the new crankshaft sensor and make sure it has a piece of paper (spacer) glued to the bottom. This spacer serves as an electrical ground. Using the CKP sensor without the spacer will break the unit the first time you try to start the engine. If necessary, you may buy the spacer through your local auto parts store or dealership parts department. Ask for part number PN05252229.
Install the new CKP sensor into the transmission bell housing mounting hole.
Start the two bolts or nuts by hand and then tighten them to 9-feet lb. (12 Nm) using a torque wrench, ratchet extension and socket. If your model has only one mounting bolt, push the new sensor against the flywheel and then tighten the bolt to 60-inches lb. (7 Nm) using a torque wrench, ratchet extension and socket.
Plug the CKP sensor electrical connector.
Lower your Jeep if you had to raise it. Remove the chocks from the rear wheels.
Items you will need
- Floor jack, if necessary
- 2 jack stands, if necessary
- 2 chocks, if necessary
- Soft brush
- Shop rag
- Ratchet extension
- Spacer number PN05252229, if necessary
- Torque wrench
- Jeep Wrangler 1987 thru 2008 (Haynes Repair Manual); Max Haynes; 2009
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