Crank Relearn

[JimmyJazz]

I need to do a crank relearn. I believe the PCM has to log the brake being applied. I have a manual gearbox. The engine is now in a car were the brake switch is not used is it possible to create this with out grounding the relevant pins on the PCM.

[Taz]

A manual trans tune usually won't set any DTCs if a brake switch is not used - an auto trans tune will. A manual trans tune does "look" for a clutch switch, and this should be used. The brake switch is a "normally closed" circuit. When the brakes are NOT applied the PCM receives ignition voltage (ie. 12 volts) on this circuit. When the brakes ARE applied this voltage to the PCM is interrupted. In Gen III trucks this circuit is normally connector C1 (Blue) pin 33.

Try executing the crank angle learn routine, and see what happens. If the routine doesn't execute, you will need to hook up a brake switch (at least temporarily) and try again.


Regards,
Taz