Just replaced my Crank Position Sensors...EASY JOB!!!

[Mark Bunds]

After several months of suffering with the typical symptoms of a bad crank position sensor (sudden stalling, power drop outs, service engine light, refusing to start at odd times, P0335/1106 codes) I finally took the time to change them out.

The job was faster and simpler than I expected. After driving the car up onto a set of ramps, I grabbed a bucket and an old towel and removed the oil filter. As the oil drained out of the filter adapter, I removed the splash guard covering the forward section beneath the engine compartment to give me room to use both hands in guiding tools and removing bolts.

I removed the oil filter and set it aside, and removed the two 10mm bolts holding the oil filter adapter to the engine block. The adapter housing has the oil pressure sender mounted to it, and the connector extends behind the front engine mount, so I had to use care when releasing the clip and unplugging the cable from the sender, but it was not hard to do.

After the oil filter adapter housing was out of the way, I unplugged the cables from the crank sensors (the plugs have a release catch that you can easily squeeze with your fingers, then the plugs come right out) it was a simple matter to remove the old sensors which are mounted with one 10mm bolt each.

The upper and lower sensors are made slightly different, so it is impossible to get the wrong one mounted in the wrong hole.

After putting everything together I noticed that less than 1/2 quart of oil drained out of the filter/adapter, and since I had just changed the oil and filter, I simply returned it to the engine. The job took 56 minutes.
She started up and runs perfectly with no more P0335 codes.

Thanks to the fine folks who posted the threads describing the symptoms and mitigation of this problem!

[Jimmieclint]

what's the trick with the connectors ?
how do you unlock ?
Pull out the Sensor and then disconnect - things are giving me greif

[Ur7x]

When I did mine I found it easier to remove the sensors with the connector attached and then unplug them.

On my 2002 they were double locking... I had to use a "pick" to take my locking connectors a part...

But the above procedure is accurate and complete, nicely writen...

As I have posted before this is only slightly harder then changing your all... And its something that ALL 2000-2003 Northstars will have to have done

[u00glp2]

Are there any cautions regarding the spacing of the sensor to a gear- or just put them in and they bottom out and are at the correct depth or air gap?
e mail me if you like at george.peveto@verizon.net
thanks gp

[Ur7x]

No, stick them in the hole... tighten the 10mm hold down bolt and plug them in.

[thu]

Mark, Thanks for the description. It will give many of us more confidence to replace them ourselves.

[Playdrv4me]

Originally Posted by thu

Mark, Thanks for the description. It will give many of us more confidence to replace them ourselves.

Indeed! Excellent writeup and very detailed. Its a shame this is such a common problem, but at least this way its easier to cope with.

[Marco]

What about the re-learning procedure for the PCM? Is that something that needs to be done afterwards?

If I take this to the dealer to have both sensors replaced & re-learned what can I expect the bill to be?
I'm getting the P0385 & P1599 codes along with car dying and SES light coming on.
Also a no-start condition on an especially hot day, then 40 mins later cranks right up.
Any help is appreciated.

[jchughes101]

I was quoted $358 for the job at the dealer but I’m not sure if that was for both or the one giving me issues. They did mention that you should replace both even if only one is giving you issues. $358 is not too bad for both if you figure that each sensor is about $73 from the dealer. Mark, where did you get your replacement sensors, purchased from the dealer or online? I could get them from the dealer with a discount for $60+ but that is still $20 more than from gmpartsdirect. I figure I will just order mine next payday and wait a few weeks for them to be delivered to save $30.

Marco:
As far as symptoms I get hard starts, some power drop outs especially going up hills, and stalls usually only when going slow.

[Ur7x]

Relearn is NOT required in most cases. The relearn makes up for small differences in manufacturing tolerances in the sensors and crank trigger thingy... The new sensors are very nicely made and I would bet (by looking at them) that there tolerances are significantly better then the "made in Mexico" ones that fail...

No DO NOT pay for the relearn process UNLESS you have driveability issues after replacing BOTH sensors. 99 time out of 100 the relearn does nothing other then lightening your wallet.

Oh ya and alway replace them both...First because they both will fail and second the computer uses one to test the other... This is one of the rare times that the computer code that says "A" or "B" is bad is really just a guess... These fail for a split second, just enough for the car to stall, and then just as fast they are both good... If the computer does post a code... it is just a coin toss.

[AJxtcman]

Originally Posted by Ur7x

Relearn is NOT required in most cases. The relearn makes up for small differences in manufacturing tolerances in the sensors and crank trigger thingy... The new sensors are very nicely made and I would bet (by looking at them) that there tolerances are significantly better then the "made in Mexico" ones that fail...

No DO NOT pay for the relearn process UNLESS you have driveability issues after replacing BOTH sensors. 99 time out of 100 the relearn does nothing other then lightening your wallet.

I think I will need to post a graph From a program I have assembled. Oh yeah I can't do that. I should post a Graph from a GM program because that is what we are talking about. The relearn must be performed. If you go to the dealer and have the sensors replaced. If they do not relearn the sensors How would you feel? Oh yeah they come back if you don't relearn the sensors. Stalling, surging, MISFIRES are the biggest reason they come back. Some don't come back, but if it was your car how would you feel? It would be like an oil change with out the filter. This is not like you forgot to reset the oil life, but forgot the filter

[Ur7x]

OK, let me clarify my post.

I have personally replaced the crank sensors, on my car - 2002 STS , on my buddies car - 2001 STS and on my sisters 3.5 shortstar - 2001 Intrigue. None of them had the relearn done and none of them have any driveability issues...

I worried about this when I did mine (first)... I thought, hey the FSM says it should be done... I should get it done... Then I got some advice from one of the engineers who designed the North*... What he told me was...
"The relearn is only required if you experience driveability issues". The tech at my dealership confirmed that they rarely do this step on the cars done there.

I would say you might be surprised how few relearns are done even at dealerships.

[Intheknow]

What is the process of the relearn?

[Ur7x]

This is process that can basically only be done at the dealership. They hook up a Tech II and they recalibrate the ignition timing based on several RPM check points.

Again, the technician at my dealership told me that they only do this if the car stumbles or misfires after the new sensors are installed. If you are replacing these yourself. Drive the car and see how it is... Maybe try a WOT or two.. If there is no stumble stall misfire, etc... Then like the three cars I have done the relearn was redundant.

[Marco]

Thanks JC, UR7x and AJ.

I guess I will replace the sensors on my own first and see if there are any problems from there.

I would dread having to take it to the dealer for relearning, I can see potential problems there...

"Well, we didn't install the sensors so we wouldn't be able to guarantee the procedure, blah, blah, blah."

Btw, Sewell Cadillac in San Antonio quoted me $490 to replace both w/labor.
Thanks again guys!