Friend has an 06 duramax/allision totally stock and is having a problem thowing a tranmission code that says communication with ecm lost. I am thinking that maybe a pin in the harness isn't making good contact, but what would be the best place to start, back of tranny plug or at ecm? When I clear the code, it stays gone for a few days up to a month. When the code sets, it shifts like it is in tow haul. I can't remember the code number, just the description.
2006 communication problem
- Thread starter nuffsaid
- Start date
does it only throw loss of TCM comms codes? Or does it also throw loss of glow plug control module codes?
if it only sets loss of TCM comms codes, then start at the TCM connector. Reason I say that is because the ECM, TCM, and GPCM are all on the high speed GMLAN data bus; so if the problem is at the ECM connector, it would throw a loss of comms with both other modules codes..
make sense?
ben
if it only sets loss of TCM comms codes, then start at the TCM connector. Reason I say that is because the ECM, TCM, and GPCM are all on the high speed GMLAN data bus; so if the problem is at the ECM connector, it would throw a loss of comms with both other modules codes..
make sense?
ben
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It is actually throwing a code that says loss of communication with ecm, not tcm. I can't remember the actual code number, I will write it down next time it comes up. The code is always stored on a cold start up. this truck is garaged all the time.
I am going to have to wait for the truck to throw the code again. I wrote the code down somewhere, just can't remember where. It went a couple of months without throwing, now it has thrown twice in a week. Since I haven't driven truck with the code active, I can't really describe what it is doing. Friend just says it drives different, stays in gears longer.
This almost sounds like hot mode strategy when the Alli overheats. What the trans temp next time it codes.
Funny thing is that it is coding when everything is cold, it does it immediately after being started in the morning. Truck is kept in heated garage, and I am not sure if it has anything to do with being run in 4wd on snowy roads. 1st time it did this was over a year ago, I cleared the code and it went 8 or 10 months before doing it again. Now it has been several times in the last month. Code never stays after it is cleared and drivability always goes back to normal. Maybe next time it codes, I should log some real time data and see what looks to be out of whack.
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