What conditions would dictate a crank relearn procedure?

I just replaced my tranny and now my car has a bad miss after the install.
We did rotate the crank with the battery disconnected to take out the converter to flexplate bolts..

Did you guys think its outta whack and causing the car to miss now? Before this the car was running great...other than a slipping tranny.

Thanks,
Jeremy

 

You are supposed to do it when you put a new crank in or when a new crank sensor is installed. Shouldn't have to do it when a new trans is installed.

 

Phucking car, It was running great before the swap and now it has a big misfire.

Figure since we turned the crank/flexplate to get to each converter bolt then "maybe just maybe" it threw the PCM for a loop and now its lost at where the crank was before all this crap.

 

Rotating crank does not cause PCM to get lost unless different converter 'bolting angle' to flexplate results in worse weight inbalance. Did the flexplate get any damage during the install ? Same converter ?

 

Also a new motor with your original PCM, which is in effect the same as a new crank.

 

Dang, I never did a crank relearn with my new 408. Woudl I be hurting anything? Sounds fine...

 

My thought was it's about 5 minutes if you own HPTuners to do it so I did.

 

Ok, quick how to?

 

Flexplate wasn't even remotely harmed in anyway, just unbolted the converter, the tranny slipped away from the engine very nice.

Same converter as well.

Maybe we managed to snag a wire on something. The starter did take a free dive off the kmember with its harness attached...maybe something got messed up there.

I'll do a crank relearn just for ***** and giggles tho, since its pretty easy to do with HPT.

J

 

I'm pretty sure the CKP relearn does nothing but help the computer detect misfires. I have had 3 different PCMs in my car and 2 different motors and never did a relearn. I would now but it runs so good I'm afraid to touch it lol.

Make sure you didnt pull a plug wire off or pinch/pull any of the injector or coil wirinng anywhere also. Could have damaged the wiring to the crank sensor also..

 

"Ok, quick how to?"

Open the scanner, pick displays, VCM controls:

CASE Learn: To use the CASE learn function please follow these steps:

1. Put the vehicle into park (auto) or neutral (manual).
2. Turn off all accessories and A/C.
3. Apply the parking brake.
4. Press the brake pedal. Keep the brake pedal depressed during the entire procedure.
5. Press Begin.
6. Gradually rev the vehicle to fuel cutoff (around 4000-5000 RPM's) over a period of about 4 seconds. When fuel cuts out, immediately release the throttle.
7. Allow the engine to come back to an idle.
8. Turn the ignition off for at least 15 seconds. This step is required for the VCM to store the newly learned configuration.

 

Yeah i'll be checking that area real good Kev, having to replace the oil level plug/wires anyway...but you know that story already

 

Did you rip the oil level plug wires out removing the starter?

I did

 

my uncle did

I broke the starter Damn slippery hands

 

Starter connections on top + short wiring harness = the suck

 

It helps the PCM know when to inject fuel and spark also ... I've had a few times where I swap to a different PCM, car will barely start, backfires to hell... it helps the PCM know where the CAM is in relation to the Crank so it knows what part of the 4 cycle process it's on...

Most of the time, I've swapped PCMs no problem... but every once in a while I've run into the issue above... and a crank relearn has fixed it every time