How to Remove a Buick Crankshaft Sensor

by Dan Ferrell

The process to replace the crankshaft position (CKP) sensor on many Buick models is rather involved, since you must remove the drive belt and balancer/pulley from the crankshaft. Then you will reset your vehicle computer using a scan tool. Read through the entire procedure first before attempting to remove the sensor, and make sure you have the special tools required.

Removing the Crankshaft Sensor

Open the hood and disconnect the black (ground) battery cable using a wrench.

Remove the drive belt following the specific instructions in your car owner's manual. On some Buick Century models you do not need to remove the drive belt. Read Step 7 for reference, and continue with Steps 3 to 7 if necessary.

Loosen the front passenger-side wheel lugs using a lug wrench.

Raise the front of your Buick using a floor jack, and support it on two jack stands.

Finish removing the wheel lugs from the front passenger side wheel using the lug wrench; then take the wheel/tire assembly off the wheel hub and set it aside.

Remove the splash shield cover using the ratchet and socket.

Locate the crankshaft sensor on the side of the engine block, if you have a Century. Some, but not all, Century models have the CKP sensor bolted to the engine block below the spark plugs and wires area. Unplug the electrical connector and unscrew the sensor mounting bolts to remove the sensor from the engine using a ratchet and socket. If you have a different model, continue with the rest of the steps.

Ask a helper to hold the flywheel using tool No. J-37096 (flywheel holder) or equivalent and a ratchet as you unbolt the crankshaft balancer/pulley assembly with a ratchet, ratchet extension and socket. (See Resources for more information.)

Detach the balancer/pulley from the crankshaft using tool No. J-38197-A (harmonic balancer puller) or an equivalent pulley puller (see Resources for more information). Use the 1/4-inch bolts that come with the tool to install the puller on the balancer/pulley assembly, and screw the bolts 1 1/4 inches into the pulley.

Unscrew the three mounting nuts from the crankshaft position sensor (CKP) shield using the ratchet, ratchet extension and socket. Then remove the shield. Some Century models do not have this CKP shield.

Unplug the CKP sensor electrical connector. On some Century models, you must remove the CKP sensor harness-retaining clip before you can unplug the sensor. Use a ratchet and socket, and make a note of the harness routing for proper installation.

Unscrew the two CKP-sensor mounting stud bolts using a wrench or ratchet, ratchet extension and deep socket.

Remove the CKP sensor from the vehicle.

Installing the Crankshaft Sensor

Install the CKP sensor, and tighten the mounting bolts using the ratchet and deep socket.

Plug the CKP sensor electrical connector. If you have a Century model with the sensor mounted on the side of the engine, you can lower the vehicle now and reconnect the black (ground) battery cable using the wrench. Otherwise, continue with the rest of the steps.

Set the crankshaft sensor shield in place and tighten the three mounting nuts using the ratchet, ratchet extension and socket, if your Buick model is equipped with this shield.

Install the balancer/pulley on the crankshaft, and tighten the bolt using the ratchet, ratchet extension and socket. Ask a helper to hold the flywheel using tool No. J-37096 or equivalent as you tighten the bolt.

Install the splash shield cover using the ratchet and socket.

Install the wheel/tire assembly, and tighten the wheel lugs enough to hold the wheel firmly against the wheel hub using the lug wrench.

Lower the vehicle and finish tightening the wheel lugs.

Install the drive belt following the instructions in your car owner's manual.

Reconnect the black (ground) battery cable using the wrench.

Perform the CKP system variation learn procedure using a scan tool. Consult your car owner's manual for the proper instructions for your particular model.

Items you will need

References

About the Author

Since 2003 Dan Ferrell has contributed general and consumer-oriented news to television and the Web. His work has appeared in Texas, New Mexico and Miami and on various websites. Ferrell is a certified automation and control technician from the Advanced Technology Center in El Paso, Texas.