My buddys truck wont go into overdrive and we cant figure out why. The truck is a 96 2500 4x4 with an auto of course. When I hook up the scanner the trans temp reads 14663 degrees. I know that must be why it wont shift od but what could cause that to be so high? We changed all the selonoids in the trans already and that didnt change anything except now it will start out in second gear unless it is manually shifted then it will go to first.

 

Did you check the temperature sender?

 

The temp sensor is in the selonoids that we replaced from what i understand.

 

I think the sensor on those years is on the oil cooler line, but I am not sure.

 

I dont see a sensor inlene so it must be in the trans.

 

Only '94 & '95 have the sensor in the cooler line.

If the sensor is new then I'd suspect a bad connection or wire.
If you know which two wires the sensor feeds you can disconnect the sender and short across the two wires with a 1000 ohm resistor to trick the PCM into normal operating temp.
Might try doing it at the tranny as well as at the PCM.

 

I have the resestor but i am not sure what wires to jump.

 

Are you sure it's not really 14663 degrees? What's he been pulling? Has been driving on the sun lately?

 

That's where the factory service manual comes in handy.
One thing I know for certain is that wire colors vary more than anything else from year to year.

 

Now it set a code p1765 and it says the trans temp is -86 degrees. I hope to get a wiring diagram today.

 

ok i did the resistor thing and it shifted od a few times on the jack then when i test drove it it shifted od once. then the od light came on and the trans temp light and no more od could i have the resistor in backwards does it matter.

 

Doesn't matter which direction the resistor is in.
Perhaps it isn't making good contact.

 

it is soldered in but i will check it

 

I hate this truck I want to set it on FIRE!!!! Now it blew a brake line.

 

Swaped out the pcm with one from another buddys truck ant the trans temp numbers and everything were normal. It tried to shift od but it still aint right. I think it has a bad pcm and some internal od problems.