View Full Version : Crankshaft Sensors

03-05-11, 06:02 PM
I am needing to replace my crankshaft sensors in my 2002 deville. i have never done this before and dont know what im getting into. any suggestions or pointers to make this as easy as possible?

03-05-11, 06:34 PM
Faulty CKP's will signal with a slow speed warmup stall or slowdown stall.

Why do you need to replace the CKP's ?? Faulty DTC's (Diagnostic Trouble Codes) in the car's built-in code system ?? You're looking for P0335/6 and P0385/6 and maybe others.

There are 2 - A & B - new models made by DENSO in Japan. One black, One gray. They're mechanically different, so will only go into the correct hole. 10mm wobble socket, and a lot of patience, car up on a hoist. Remove the lower air deflector and, for more room, the oil filter adapter. The electrical connectors are double locked - no fun to disconnect.

Black = GM #12575482
Gray = GM #12575481

00 Deville
03-05-11, 06:40 PM
The oil filter adapter comes out fairly easily and really opens things up... especially if you have large hands. Does the car have the original CKP's if so what is the mileage?

03-05-11, 06:40 PM
thank you. do i need to disconnect the battery while i do this or is it ok? whats the best way to disconnect the the double locks?

03-05-11, 06:41 PM
I actually just got the car 2 weeks ago so im not sure? the car has 120,000 miles tho

03-05-11, 06:44 PM
thank you. do i need to disconnect the battery while i do this or is it ok? whats the best way to disconnect the the double locks?

No need to disconnect the battery - the power to the CKP's is ignition ON dependent.

Electrical connectors: patience and small hands. Snap locks.

Again - Why do you need to do this ? Do you have driveability problems ??? If so, it might be something else unless you have narrowed it down by using your diagnostic codes.

03-05-11, 06:46 PM
oh and i need to replace them cause i got a service engine light and it through codes po385 and po335 which are malfunction sensors, it also put out a po420 dont know exactly what that is yet?

00 Deville
03-05-11, 06:48 PM
I didn't disconnect the battery when I did mine. If the car has the original CKP's I would definitely change them... the original CKP's are tan or brown in color... if the are the new style CKP's they are Black and Gray as Sub said. It would be unusual but not unheard of you to make it to 120K with the old POS CKP's.

Are you experiencing any drive-ability issues... car stalling or shutting off?

03-05-11, 06:51 PM
P0420 is a catalytic converter efficiency code. If you have/had CKP codes which show as Current, then it's possible that the ignition timing has defaulted to a fixed 10 degrees BTDC and something has gone wrong with fuel/air mixture.

Your car has an O2 sensor in each exhaust manifold and one after the cat - when the emissions system shifts loops at 160 degrees coolant temp, the sensors are compared for output. The after-cat sensor (B1S2) is saying that there's something fishy with the cat or fuel mixture.

03-05-11, 07:06 PM
it actully just shut off on my wife today. thats why i am gonna replace them. i got the engine checked and they turned off the light and said if it comes back on soon they probly need to be replaced. i plan on doing it monday morning, is it ok to drive till then?

03-05-11, 07:08 PM
what fuel should i be running? i think my wife used regular once at most twice but i have put premium in since. could that be why?

03-05-11, 07:18 PM
Sure it's OK to run regular - the 2000+ Northstar is set to run on 87 and it's so stated in your owner's manual. Unless you race the car or pull a trailer, running premium will do exactly nothing for performance or gas mileage. Nothing. I run 87 Shell or Chevron (Google "top tier gasoline" to find out why) all the time; rural, highway, Interstate, up to 143 mph - no troubles for 5.5 years.

It's OK to drive the car, BUT be ready for an unexpected slow speed or coastdown stall during warmup.

If you're going to do the CKP's yourself, talk to Chris at Rippy Parts up in Vendors ^^^. He's a Cadillac parts man.

While you're waiting, read and study the sticky post ^^^ "How to pull codes". Your car has its own built-in code reader/scanner/memory. You can sit in the driveway and read exactly what's going on. You get the codes, write them all down, whether they're Current or History, then return to the sticky and open the link with "obd2" in the URL to get to a Master Index of links to all P,B,C, and U codes.

P = Powertrain
B = Body
C = Chassis
U = voltage and data stream

03-05-11, 07:36 PM
Ya i will def. do that thank you so much for all your advice and input. it has been very helpful.

03-05-11, 07:40 PM
After dinner, make a decent scotch and water and go to Discussions; Technical Tips. There are 9 pages of "How to" threads on just about any sort of engine, transmission, body, suspension, electrical problem you may have...............