: Crank Position Sensor Symptoms and Replacement



turbojimmy
03-12-05, 01:50 PM
Hi all,

I was getting a P0386 consistently every couple of times I started the car. The code has not reappeared for about a week now but the car does stall at random (consistent with others' stories about bad crank sensors). The engine will also 'shut off' while accelerating and then 'turn back on'. No codes. Could this also be the crank sensors?

So I ordered a pair of crank sensors. They don't look too hard to replace. The manual says to run the CKP system variation learn procedure after replacing the sensors. Is this critical? Or can I just pop the new ones in and forget about it.

TIA,
Jim

mcowden
03-12-05, 04:25 PM
It does sound like a crank position sensors problem. I don't know about the learn procedure, but unless I'm misunderstanding how those sensors work, I'm not sure what there would be to calibrate or "re-learn." Bbobynski?

01STS
03-12-05, 08:47 PM
Good question. I am having the same issues but get a P0335 code for the "A" sensor. I was thinking on attempting the repair myself but if you need a tech2 to reprogram them.......

tttjump
03-13-05, 11:34 PM
I just replaced two ckp sensors. Took about 45 minutes. I did not do a relearn procedure. Codes are clear, cars starts up and does not stall so far. What does the manual say about a relearn procedure? I had both codes for the A and B sensors. 2000 STS.

turbojimmy
03-14-05, 05:32 AM
I just replaced two ckp sensors. Took about 45 minutes. I did not do a relearn procedure. Codes are clear, cars starts up and does not stall so far. What does the manual say about a relearn procedure? I had both codes for the A and B sensors. 2000 STS.

How about your symptoms? Did it buck or stumble at part throttle?

The manual says that after you replace them you need to run the CKP System Variation Learn procedure. From what I understand, the procedure learns 'normal' crankshaft variations so that the PCM can tell the difference between 'normal' and a misfire. My interpretation is this: The normal crankshaft variation wouldn't change by swapping out the sensors, but the new sensors may be reporting slightly different values and could cause a P0300 error when no misfire actually exists.

I'll just swap them out and see what happens.

Also the manual says to remove the motor mount in that area, but nothing about the oil filter adapter. tttjump: which do you think is easier?

Thanks!

Jim

tttjump
03-14-05, 10:30 AM
I would not do the motor mount. I attempted that at first becuase it is right in front of the sensor and seem to be the easiest. I then tried the oil filter housing, two bolts 10mm, the oil filter housing has two o-rings that may need replacing. Once the housing is removed the sensor take about 5 minutes each to replace. The oil filter housing takes about 10 minutes to replace. Total time took about 25 minutes. The sensors pop out, push on them when putting them in until you hear them pop back in. Make sure to put oil on the o-ring on the CKP sensor before installing them.
I replaced them becuase the ckp code for the b sensor was coming on and the car would stumble, stall or take eaxtra cranks to start. The code for the A sensor started coming on when the B sensor went away. They both came on and the car would die and not restart. It took about 5 months from when the trouble started for the car to completely not start.
The car started up right away after replacing the sensors. It does run a liitle rough at idle. Does the manual say how to do a relaern procedure?

Hope that helps

turbojimmy
03-14-05, 01:58 PM
It does run a liitle rough at idle. Does the manual say how to do a relaern procedure?

Hope that helps

It does help - thanks.

The dealer has to do the CKP relearn procedure with the Tech2. It was just done on my car when they reflashed the PCM so I don't want to pay to have it done again. My idle is a little rough, too but then so is my dad's '02 Deville. It was the first thing I noticed about it. It's very, very subtle, but it's there. Almost like a miss.

The stumble, stalling and P0386 code have not returned in about 150 miles and about 15-20 starts. I'm going to keep the sensors since they're on their way, but I'm not going to mess with them unless things get worse.

Jim

tttjump
03-14-05, 07:14 PM
Hello, well just hope that when they go they dont leave you someplace far from home. Mines got to the point where it would not stall until after it warmed up and then it would take about 20 minutes before it would retstart. Good thing the battery was well charged. Any one else know anything about the relearn procedure? How much did the dealer want to do the relearn procedure?

turbojimmy
03-14-05, 07:40 PM
Hello, well just hope that when they go they dont leave you someplace far from home. Mines got to the point where it would not stall until after it warmed up and then it would take about 20 minutes before it would retstart. Good thing the battery was well charged. Any one else know anything about the relearn procedure? How much did the dealer want to do the relearn procedure?

Yeah, I like to live on the edge. I've got AAA Plus which gives me an extended towing range. I don't venture more than 25 miles away from home on a typical day. I took it to work and back today (15 miles each way) and it was fine.

I don't know how much the learn procedure was, it was lumped into the hours they spent reprogramming the car after I swapped out all of the modules.

Jim

tttjump
03-14-05, 07:51 PM
Here is a website the explains the learn procedure and the when and the why
http://www.seattleautomotive.com/ckpdoc.htm
I also found a website the mentions something about recalibrating the controllers.
It does mention the dealer and a tech2 scan tool.

haymaker
03-14-05, 08:43 PM
Here is a website the explains the learn procedure and the when and the why
http://www.seattleautomotive.com/ckpdoc.htm
I also found a website the mentions something about recalibrating the controllers.
It does mention the dealer and a tech2 scan tool.
That was very interesting, so even the removal of the harmonic balancer may cause a CKP trouble code to be set.

turbojimmy
03-15-05, 06:41 AM
That was very interesting, so even the removal of the harmonic balancer may cause a CKP trouble code to be set.

It is interesting. It's the same explanation that's in the manual, I was just too lazy to type the whole thing.

I swapped PCMs in my car and the first thing that happened was it stored a DTC for the 'relearn CKP variation'. When the dealer tried to run the test they couldn't get it to run. After goofing around with it they found that my TPS was bad and my TCC switch was always open. So the labor for the test was lumped into all the other stuff they did in order to get to the point where they could run the test. It can't be that much to have them run it. If I do change my sensors out I'll inquire as to the cost of the test.

Jim

Logandiagnostic
03-15-05, 10:11 PM
My 2001 had one go bad about 18 months ago. Strange but true....I had one sitting here that was sent in with a brake light core from a dealership.

It was the older style....but worked ok for that 18 months. Now it starting to act up....funny starts....stalling....

Anyway, picked up 2 new sensors today at Cadillac for about $90.

As for the learn procedure...here it is.....



CKP System Variation Learn Procedure
After the powertrain control module (PCM) learns the amount of crankshaft position (CKP) system variation, the PCM stores the compensating values in the non-volatile area of the electrically erasable programmable read only memory (EEPROM). If the amount of crankshaft variation is outside the stored values, DTC P0300 may set. Refer to Diagnostic Aids for DTC P0300.

The Crankshaft Position System Variation Learn Procedure should be performed for any of the following conditions:

DTC P1336 is set
PCM replacement
Engine replacement
Crankshaft replacement
Crankshaft position sensor replacement
Any engine repairs which disturbs crankshaft to crankshaft position sensor relationship

Caution
Before performing the Crankshaft Position System Variation Learning Procedure always set the vehicle parking brake and block the drive wheels in order to prevent personal injury. Release the throttle immediately when the engine starts to decelerate in order to eliminate over revving the engine. Once the learn procedure is completed, the control module will return engine control to the operator and the engine will respond to the throttle position.


Set the parking brake.
Block the drive wheels.
Ensure the hood is closed.
Start the engine and allow engine coolant temperature to reach at least 70C (158F).
Turn OFF the ignition .
Select and enable the crankshaft position variation learn procedure with the scan tool.
Start the vehicle.
Apply and hold the service brake pedal firmly.
Ensure the transaxle is in park.
Increase accelerator pedal position until the fuel cutoff is reached at 5,150 RPM. Immediately release the accelerator pedal after fuel cutoff is reached. The crankshaft position system variation compensating values are learned when the RPM decreases back to idle.
Observe DTC status for DTC P1336.
If the scan tool indicates that DTC P1336 ran and passed, the crankshaft position system variation learn procedure is complete. If the scan tool indicates DTC P1336 failed or not run, check for other DTCs. If no DTCs other than P1336 are set, repeat the crankshaft position system variation learn procedure as necessary.



Logan Diagnostic
www.ledfix.com
www.airbagcrash.com

turbojimmy
03-16-05, 05:31 AM
Thanks for the info Logan. The symptoms took a 2-day hiatus, but yesterday it stalled in my dad's driveway. Just once. I then made a 100-mile round-trip trek without incident.

I need to go through emissions inspection again on Friday. They failed me for emissions because I didn't have enough mileage on the PCM (failed the 'operational readiness' test - what load of crap). They didn't even check it for emissions - just plugged into the OBDII port. Rejected. Hopefully the P0386 will stay away long enough to get a good sticker on the car. The P0386 has been gone for over a week now and hasn't returned. It's still too cold in this neck of the woods to be rolling around in the driveway under the car.

Jim

turbojimmy
03-18-05, 08:12 PM
I would not do the motor mount. I attempted that at first becuase it is right in front of the sensor and seem to be the easiest. I then tried the oil filter housing, two bolts 10mm, the oil filter housing has two o-rings that may need replacing.

I attempted the motor mount. It's ridiculous. I gave up and it took me 45 minutes to get the 4-bolts back in the motor mount bracket. The service manual says that to replace the crank sensors that you need to remove the motor mount, which requires removing the engine cradle. Hours and hours and hours of labor. Yet the book says the crank sensor replacement is 1.1 hours.

So, I'm back at square one and I'm going to take your advice like I should have in the beginning.

Did you have to replace the o-rings on the oil filter housing? If so, where did you get them?

Thanks,
Jim

turbojimmy
03-19-05, 06:58 AM
I replaced the sensors using the remove-the-oil-filter-housing method. It doesn't make sense to do it any other way. I started at 5:24 and was sitting in my kitchen - tools put away and hands clean - having a cup of coffee at 6:21.

Cranks less and idles better so that must've been it (plus the P0385 and P0386 were good hints).

Thanks tttjump - I should've taken your advice last night.

Jim

raymondk
03-31-05, 11:36 AM
My 93 Eldo N* had a similar problem. It would always start cold and ran seemingly perfect never stalling. But if you turned it off after 10 or more minutes of running in warm weather, it wouldn't hit a lick. Performing the diagnostic proceedure was non conclusive with the outcome being replace the PCM. I put an oscilloscope on the pickups and both had the same pattern. I then tried cooling the ignition module by rubbing a piece of ice around the aluminum part of the base across the front. This instantly cured the no start. It was 100% consistent so after several days of riding with a cooler of ice, I replaced the Ign. module. It hasn't acted up again in over 3 years. Advance Auto sold me the exact Delco module for $280.00. Gm wanted around $420.00.

BeelzeBob
03-31-05, 12:28 PM
My 93 Eldo N* had a similar problem. It would always start cold and ran seemingly perfect never stalling. But if you turned it off after 10 or more minutes of running in warm weather, it wouldn't hit a lick. Performing the diagnostic proceedure was non conclusive with the outcome being replace the PCM. I put an oscilloscope on the pickups and both had the same pattern. I then tried cooling the ignition module by rubbing a piece of ice around the aluminum part of the base across the front. This instantly cured the no start. It was 100% consistent so after several days of riding with a cooler of ice, I replaced the Ign. module. It hasn't acted up again in over 3 years. Advance Auto sold me the exact Delco module for $280.00. Gm wanted around $420.00.


Good info and good diagnosis but understand that the car in question in this thread (a 2001 DTS) does not have the ignition module. Starting in 2000 model year the Northstar engine has a coil-at-plug ignition system. The 8 individual ignition coils are controlled directly by the PCM and the crank sensor into/signal goes directly to the PCM not to the ignition module like the pre-2000 engines did.

turbojimmy
03-31-05, 12:57 PM
Just an update after a few hundred miles....it's still good. The long cranking, the random stalling and 'shutting off' up under a load were all related to the crank sensors. Codes cleared, passed emissions inspection last week.

Jim

andrewgrahamwebb
03-23-09, 08:14 PM
Hi Jimmy,

did you have gm do the reprogramming? I dont want to pay them the money. Also did the crankshaft position sensors affect your emmisions?

Please let me know, I'd appreciate it.

Andrew

Ranger
03-23-09, 09:35 PM
Normally you should not have to reprogram anything unless there is a problem. Just change them and go.

Submariner409
03-24-09, 08:44 AM
I doubt he'll get a reply to a 4 year old thread.

Failing CKP's will affect emissions if the stall/ignition systems sense that a default ignition setting (fixed 10 degrees BTDC) is required.

If you get a P0335/6 or P0385/6 code and maybe a P0300, then you should replace both CKP's with new models.The older types were Mexican/Siemens made and are subject to failure. The new series is made in Japan (Denso ?) and there is one gray, one black.

You probably won't have to do the CKP relearn procedure unless you encounter low speed driveability problems. Takes about $110 in parts from www.rockauto.com, www.gmotors.com, www.gmpartsdirect.com, or call Luke at Lindsay Cadillac parts, M-F, 9-5 EDT, ------> over there. Car needs to be up on a lift to do a proper job. Tight work.

97EldoCoupe
09-03-14, 11:53 PM
Anyone mind if I bring this old thread back to life?

My 04 Bonneville GXP......giving me quite the challenging time right now. First issue surfaced when I was making a U-Turn in Wisconsin off I-94. Traffic was heavy and I'm usually not afraid to punch the gas and get into tight places. Well it wasn't a good idea; the Northstar decided to buck like crazy.

Little by little it's been getting worse. I probably have 2,000 miles since, and the bucking and stumbling is most pronounced by take-off and cornering. I've never had this Northstar out; but another shop had done the valve cover gaskets before I purchased it. Plugs are fine, coils are fine (#8 gave out, I replaced all four on the Left bank).

Today I took my fiance to work since her SRX blew a power steering hose. I stopped at the hardware store and it wouldn't restart. Crank but no fire. I figured it was worth a shot to disconnect the battery. I did that; reconnected it; it fired right up.

This evening I replaced both CKPs. Still the same deal- bucking and stumbling on take off and cornering. I did not do a relearn.

I'm about to dive in and start checking grounds and wiring. Any ideas?

Submariner409
09-04-14, 09:24 AM
All the usual, Jake: TB and IAC cleaning, fuel injector/rail/wiring checks, CMP and wiring, PCM cables. Can you get trouble codes from the Pontiac ? Bucking (ignition/fuel miss) and stalling (ignition/fuel failure) would certainly set DTCs.

97EldoCoupe
09-06-14, 09:54 PM
Thank you Jim - I think that's next on my list, the TB and IAC. Checked the injectors (actually threw new ones in since I still have a bunch). Wiring will be right after that. I talked to my friends at DeGroote-Hill Chevrolet and they told me a crank re-learn should be done. Coincidentally, Jay (the service manager there) has a GXP as well that I fixed for him about a year ago; and his symptoms were identical and it was the IAC.

I get so busy fixing everybody else's stuff that my own vehicles get left behind. The GXP is sitting at the airport waiting for me when I get back.

Hows the 02 STS doing?

Submariner409
09-06-14, 10:26 PM
It's doing just fine - we took a run over to a "local" restaurant well east of here on Thursday for a quiet lunch, then back through rural farm country with its combination of long, flat, smooth roads and those with some weird property line angular twisties. Nothing radical with the two of us up, but I get my limited jollies and Karen puts fingerprints in the armrests. The tires suffer. I refuse to let the advancing arthritis get the best of me, so I use the various exercise equipments at the Senior Center and try to keep my driving reflexes (somewhat) honed. Next week the ol' log splitter gets uncovered and we begin working on the 2 oak trees that were cut and stacked last November..... about 1.5 cord.

97EldoCoupe
09-06-14, 11:12 PM
Jim I admire you. You're proof that age is only in the mind. And I have the same issue with my Fiance in the passenger seat, she's gotta hold on for dear life :)

I saw a tour bus from Maryland yesterday at Niagara Falls....you and Karen should come for a vacation sometime soon. Lunch is on me-

Ranger
09-07-14, 11:01 AM
What where you doing on I-94 in Wisc.? And where abouts?

I can't imagine an IAC valve being the problem. Once you put your foot on the throttle, the IAC valve becomes irrelevant.

97EldoCoupe
09-07-14, 06:01 PM
Near Madison. I still make the drive between Ontario and Manitoba now and then. I fly when I can because of time; but often it's just more convenient to drive.

Correct; the IAC only controls airflow to keep the engine idling. The throttle blade is sticking a bit so I need to clean the TB anyways. I'm still leaning toward wiring. The engine is still original; HG's holding up- but as soon as I find time I want to pull the engine and re-seal it. If there's a wiring fault in that tight area; it may be sooner than later.

Just before the car left me stuck at the hardware store; I was getting very solid shifts in every gear (default line pressure I'm suspecting). I'll pull the codes again to see if the PCM has a good reason to command full pressure but because of these that and the intermittent CKP issue I'm starting to wonder if the PCM is on the way out. I have no spares for 2004+. Time to get one.

rockhoundrob1
09-08-14, 09:54 AM
Yes, you need to do the re-learn procedure. I did not do that ( after replacing the crankshaft sensors) and the service engine light started flashing every time I drove on the highway (over 65MPH). This was for a 2002 Cad Deville.

Once I took it in for re-learn, everything was fine.

Ranger
09-08-14, 10:09 AM
That is NOT a given. In fact I think it is more the exception than the rule. I changed mine and never had a problem and I believe most people have reported the same.