transmission controller problem
Thread Starter
Teching In
Joined: May 2013
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transmission controller problem I've got a 430 hp LS3 connect and cruise package that now has a transmission controller problem. Unfortunately GM will not provide any support to a consumer, unless you want to take your car to a GM dealer and pay $100 and hour to diagnose the problem.
Finding an aftermarket controller that will work is also a problem, since the ECM and TCM communicate through the CAN system. If you unplug the transmission controller, the ECM will throw a p1682 malfunction code.
My TCM (made by PCS) will prevent any communication with the ECM, if it's plugged in.
The solution is probably just to spend $750-800 for an exact replacement TCM and move on, but at some point, it would be nice to have a product with some manufacturer's support.
PCS will not speak to a consumer either about problems with their product.
If I could reprogram the ECM to not want to communicate with a TCM, then other aftermarket TCMs might be a possibility.
Finding an aftermarket controller that will work is also a problem, since the ECM and TCM communicate through the CAN system. If you unplug the transmission controller, the ECM will throw a p1682 malfunction code.
My TCM (made by PCS) will prevent any communication with the ECM, if it's plugged in.
The solution is probably just to spend $750-800 for an exact replacement TCM and move on, but at some point, it would be nice to have a product with some manufacturer's support.
PCS will not speak to a consumer either about problems with their product.
If I could reprogram the ECM to not want to communicate with a TCM, then other aftermarket TCMs might be a possibility.
Thread Starter
Teching In
Joined: May 2013
Posts: 31
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As long as the TCM is hook-up, no device will connect with the ECM or TCM and my Speedhut gages won't work because they get their input from the same CAN bus wires used by error code readers or interfaces like HP tuners.
There is just no communication possible. There are no error codes in effect, unless I disconnect the TCM. That brings up a p1682 error code and allows a code reader to communicate.
I suspect that the TCM is junk, but I only used it for 1200 miles, a couple of years ago.
There is just no communication possible. There are no error codes in effect, unless I disconnect the TCM. That brings up a p1682 error code and allows a code reader to communicate.
I suspect that the TCM is junk, but I only used it for 1200 miles, a couple of years ago.
Thread Starter
Teching In
Joined: May 2013
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I think I have my problem solved. When I disconnected my TCM from the ECM by unplugging the bulkhead connector, the communication problem went away. I made the assumption that the TCM was toast and decided to update to the newer model TCM and wiring harness that GM offers with their connect and cruise engines.
I got the controller installed in an hour this morning and the communication problem has disappeared. I still need to connect my lap top and perform the initial setup. If all goes well, it was a simple, but expensive fix. I continue to be disappointed that GM offers no customer service for their aftermarket products.
The new wiring harness has a little longer wire from the TCM to the bulkhead connector, so I was able to get the TCM mounted in the trunk, without extending any of the wires.
I got the controller installed in an hour this morning and the communication problem has disappeared. I still need to connect my lap top and perform the initial setup. If all goes well, it was a simple, but expensive fix. I continue to be disappointed that GM offers no customer service for their aftermarket products.
The new wiring harness has a little longer wire from the TCM to the bulkhead connector, so I was able to get the TCM mounted in the trunk, without extending any of the wires.
