[MarPac]

Hi folks,

Is there anybody who knows the following: Is it possible to set up the EPC presure in the PCM using a diagnostic tool?

The thing is, that my trany is not working good when it's cold. When I shift into D, 2, 1 or R, it takes so much time to shift or I have to increase rpm up to aprox. 3000. If I do this, than the trany goes fine on R, but 1st gear slims a bit. When I drive and stop, than the gear goes out for a while.

Both servos were rebuilt, no change. Than I started to play with that using a digital oscilocsope and all schematics and found, that PCM regulates the EPC presure (using a frequency or pulse-width modulated signal into EPC solenoid) according to fluid temperature, Intake Air flow and TPS. When you increase the rpm, the pwm goes longer (longer pulses) and EPC is than bigger.

I have discovered that it seems, the EPC is regulated low, because when it's cold, the walue is not enaugh to gear the speed. If I have connected the EPC solenoid signal to LOW, the trany works without any problem (not counting the harsh shifts)

I have checked all the vacum pipes, changed the Air flow sensor and everything is OK. What about a Neutral Switch, does it have the same symptoms?

Thanks a lot, if someone has read through this. Just a few ideas about my trany :-)