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Dealer refuses to do Crank position relearn


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I just had my pcm reprogrammed and it requires a crank position relay (people i had tune it said i should do it because i gave the a truck 5.6 pcm instead of a 5.7). THey said the tune would still work but require a crank position relearn. SO i take it to TWO local dealers and they are scared to touch the car because its not a chevy.

 

My question is there someone locally (orange county, California) who can do this for me? im looking for either a shop or someone who has a Diy programmer who can do a crank position relearn without reflashing the pcm.

 

can anyone help? im pretty much screwed without it.

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You should be glad that the dealer didn't perform the job for you lol... here is the relearn info right out of my tech manuals.

 

"Certain learned values, such as: (but not limited to)

 

fuel trim (previously known as block learn memory),

IAC learned position in various park/neutral and air conditioning on/off combinations,

certain OBDII diagnostic thresholds,

automatic transmission shift adapts

will revert back to their unlearned starting point values after a reprogramming event occurs.

 

It is feasible that the engine or transmission might temporarily operate differently after a reprogramming event, until these values are re-learned. Relearning occurs while operating the vehicle through normal driving routines. If the same download files are simply reinstalled, any changes noticed in engine operation will likely disappear in a short amount of time and/or driving distance."

 

Relax, I have the same issues with my swap too. This is because I don't drive the car much and I disconnected the battery all the time. So the PCM can't do a relearn. Good luck.

V.

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Relearning occurs while operating the vehicle through normal driving routines. V.

 

 

I just found something that may answer your question. Right out of my tech manual again:

 

 

"CKP System Variation Learn Procedure

 

Important

While the learn procedure is in progress, release the throttle immediately when the engine starts to decelerate. The engine control is returned to the operator, and the engine will respond to throttle position after the learn procedure is complete.

 

 

Install the scan tool.

Apply the parking brake.

Block the drive wheels.

Close the hood.

Place the transmission in Park if the vehicle has an automatic transmission, or in Neutral if the vehicle has a manual transmission.

Idle the engine until the engine coolant temperature reaches HC (150°F).

Turn OFF all of the accessories.

Apply the brakes for the duration of the procedure.

 

Important

If the CKP System Variation Learn Procedure cannot be completed successfully, refer to DTC P1336 for additional diagnostic information.

 

 

Use the scan tool in order to enable the Crankshaft Position System Variation Learn Procedure.

Slowly raise the engine speed to 4,000 RPM.

Immediately release the throttle when the engine speed decreases.

Turn OFF the ignition for 15 seconds after the learn procedure is completed successfully. "

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Man the more I look the more I think I have the same problems as you. I have 98 C5 motor and I installed a 99 C5 PCM. My motor has some surging and misfire problem. I just did a search on my EFI Live manual here is what I find:

 

CKP learn…

Performs a crank position sensor relearn.

A relearn is necessary anytime that the physical relationship between the crank and the crank position sensor is disturbed, or if the PCM is replaced. (LS1/LS6 only)

 

This function is under the Bidirectional tab in my EFI Live Scan tool. Look like you need to find someone locally with an EFI Live or HPTuner software to help you out. I am not sure you will need to buy a license or not. Your best bet is to call John at Speartech. Good luck

V.

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You need to find a younger guy at one of those dealerships who likes fast cars and will do this for you out in the parking lot for CASH! I do stuff like this for people at work all the time. Some times it's better for everyone if there's no paper trail. This way there's no liabilty for anyone because no one can prove anything. You find the right guy at one of those dealerships and you good to go forever with this kind of stuff.

 

Here's how I would go about it, call into one of those dealerships and ask to speak to one of the mechanics. Tell them you have some questions on some performance parts for a "Camaro". This will most likely get you in touch with someone who likes performace cars and can help you with you situation.

 

Guy

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Anyone with a bidirectional tool can do this apparently.

If you're member of a local forum, ask for someone with EFILive or HPTuner as those are bidirectional and can do this.

 

Here's an interesting link:

http://www.fullsizechevy.com/forums/general-discussion/performance/164702-gm-computer-relearn-procedure-including-crankshaft-relearn.html

http://www.ls1tech.com/forums/showthread.php?t=463173&highlight=CKP

 

Good luck!

Mario

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It may not apply here but I believe the two pcms are physically the same assuming both had either an auto (for pinout to the auto tranny) or manual transmission (some have the wiring for an auto tranny anyhow). In such a case, I have approached a dealer with PCM and a good VIN is hand. The VIN must be from a vehicle with the proper engine/transmission combo. They would flash it for a few dollars if I would not hold them responsible for functionality afterwards. Once done, the pcm can be flashed with applicable software to meet your other demands.

The dealer would NEVER touch my non-chevy vehicle to scan or flash even if the driveline and electronics were stock GM. They actually appeared to be totally baffled that such a conversion could be done. Sadly, I have found that the mass of GM techs are clueless unless they are following the FSM line by line.

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I just did a CKP relearn on my engine and it ran a lot better. No more surging and no more misfire. The relearn procedure is very easy. You just need someone with scan tool. Here are the steps for HP tuner scanner:

1. Get the engine up to operating temp.

2. Use the scan tool to connect to the PCM.

3. Go to Bidirectional menu and select CKP learn

4. A window will pop up with 4 small window shows 4 sensors

5. Wait until all 4 sensors go green then the Start CKP learn button will lid

6. Leave the car idle and hit the Start learn button

7. Raise your RPM up to 5K

8. As soon as the engine RPM suddenly drop then let the gas pedal go

9. Shut the car off for atleast 15 seconds. This is where it saves the new parameter.

10. Then restart the car and test it out.

 

Good luck

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