[ChrisLyter]

Hi,well one day my tranny was going into limp mode and I could disconnect the battery and reconnect it in ten minutes and it would be ok to drive.Well one day it keep doing it everytime I shut it down till it would not come out of limp mode.I took it to a trannyplace and they could not figure it out,he could get into all the other computors except the TCM,so I got a refurbished TCM and that didn't fix the problem.He said that the ecu had no communication with the TCM,they wanted to replace it with a different transmission,I couldn't do that.So what I'm asking I guess is does anybody else have an idea.he said mechancly the transmission was not receiving anything from the TCM,I have no speed odometer or tach and no tranny lights or gas gauge,everything else works as it should,all the other stuff on the dash,any suggestions?

 

[valiant67]

If there is no communication the first thing would be to check the wiring between the modules.
Sometimes a bad instrument cluster (as in bad solder joints) can interrupt communications between the various computer modules.

 

[Doug D]

No sense in replacing anything until the communication issue is resolved.

Okay - Valiant beat me to it. Yes, among the first things I'd check is the instrument cluster.

Oh and Welcome to Allpar!

 

[Oklahoma Wolf]

He said that the ecu had no communication with the TCM,they wanted to replace it with a different transmission

That's like saying, "Car won't start? We'd better replace your engine, just to be safe."

Agreed on checking the CCD bus wires between the modules. If they're good, move on to the power supply to the TCM. Cluster solder issues are always a concern as well.

 

[ImperialCrown]

Any PCM or TCM fault codes? The instrument cluster can also store fault codes.
The dealership level may offer better diagnostics for this. It may be a bus problem.