Engine/Transmission (1998.5 - 2002) Trans. limp mode

[DWest]

I started posting on this several months ago where my transmission goes into limp mode after warming up. We first replaced the solenoid in the valve body and it went away for a week. Then we installed a resistor in the line from the pcm to the transmission, that worked for a while then it returned. Next I took it to the dealer and they sent me home with a new prssure sensor that I installed and all was fine till 3 weeks later it does it again. The code it would post said solenoid pressure sensor voltage to high. Now it's doing it all the time, even when not towing. After I installed the pressure sensor it didn't do it till one day when I was in a hurry to get to my bow stand I broke the speed limit in good fashion. Could this be a problem with a voltage regulator or even my alternator. The truck has 170,000 miles on it and the alt. is original. Dave Goerend has been a lot of help to me but I'm looking for some other ideas. The dealer said my truck has the latest program in it also. DWest

 

[Allnew2Me]

My truck just started throwing 3 codes only when cold. P0743, P0753, and P1765. I can clear them and they won't come back until the truck is cold again. They are all electrical faults, TQ, solenoid A, and manufacturer electrical. The truck does not go into limp though, the CEL just comes on.

The last time the solenoid went out it did go into limp but that was corrected when it was repaired. I also have the resistor in the PCM line and that solved the new Suncoast VB code issue.

You might try checking the connections at the resistor to make sure they are not broken, and also check any taps into the PCM wires. I have a Banks brake and trans lock and they used the 3M taps on the PCM wires. I removed them and soldered them all to avoid any corrosion issues.

I have a spare trans solenoid sensor I am going to install to see if that cures my troubles, but you did that already.

Did Dave Goerend say it was alternator related? The PCM contains the regulator circuitry so that could be possible I suppose, but I would think you would see other codes more related to charging.

 

[DWest]

Alt.

No, Dave did not say that I'm just reaching for straws. My partner has a 04 Ford and he had some weird issues that were related to his alternator. Thanks for the reply!