fyi I swapped motors, cams, all that and it did NOT need a relearn.

 

So how will crank re learn effect the car if not done?

 

See this:

 

When I had this problem after a motor/PCM swap my car woudn't make any power, wouldn't rev over ~4000 RPM, trans ran in limp mode and it had an SES light on the dash. Instantly fixed with CPS relearn procedure...

While this SES code is designed to set when the PCM does not know the crank position and cannot accurately predict/detect misfires, that's only half the story. The rest of the story is how the car behaves when this code is set, especially A4 cars.

Rob (Bad30th)

 

It did this because it was falsely detecting misfires... the PCM had bad CASE relearn data, so every crank event looked like a misfire.

The PCM always knows the crank position... the CKP reluctor wheel is fixed to the crank, it can never lose its position;

the CASE relearn measures the crank's rate of deceleration on fuel cutoff and stores it for future reference... by comparing each crank event against this the PCM can detect misfires.

 

I know it's an old thread but a local tuner told me the crank pos. be relearned by unplugging the harness to the sensor put the key to on position for a few seconds the. Turn key to off position and plug it back in. I was kinda skeptical about it since Iv searched and searched but found nothing about it without a scanner. Can anyone tell me if it works or he was bs-ing me.

 

That is for resetting the throttle position sensor, not the crank position sensor.

 

Thank you. I made it especially clear I was talking about the CRANK POS. sensor but guess it didn't click in his head.

 

I have an LS2 in my RX7 and have the same code, part of the relearn procedure requires you to keep your foot on the brake, given that my brake pedal has no input to my PCU I am assuming I will not be able to do a relearn???

 

Im in the same boat what did you come up with.

 

So far nothing, I am currently trying to find what wire needs to see the 5 volts to simulate the brake pedal being pressed. Once I figure that out I will use a power supply to feed it the required voltage.

 

It's not 5V, it's 12V from a fused source.
The pin where the signal goes to is different for each vehicle. Which is yours?

 

How can i figure this out with a chevelle and a 03 lq4 swap. Ive got a stand alone harness and computer from psi conversion.