GMC Terrain, Equinox, and SRX Forum banner
1 - 5 of 5 Posts

· Registered
Joined
·
2 Posts
Discussion Starter · #1 ·
So I have a 2009 chevy equinox LT with the 3.4L engine and was getting stabilitrak light and one day the car did it want to move when put in gear only park worked. when scanned codes P0700 transmission control system MIL request and U0100 Lost communication with ecm/pcm A. Had TCM repaired was told there was a software error. After it was repaired it drove fine for like a week and then stabilitrak came one one day with a beeping sound while I was driving and the gauges were going up and down while it did this. Used scanner when I got home and now I’m getting P2544 torque management request input signal A P150C which says refer to vehicle service manual U0073 control module communication bus A off and U0101 Lost communication with TCM. Was driving to set smog monitors but they would also never set the would say my ready some would set but then go back to not ready when I checked again. I am stumped and the dealership where I live has no idea what I’m talking about when I ask them
 

· Registered
Joined
·
2 Posts
Discussion Starter · #3 ·
Check your battery first. Many people on this site have had multiple unrelated codes when the battery was dying
We had the battery tested and it said it was good. Only thing I can do is ask them to put it on the charger that does the load test and see what happens. I’m thinking it may be the ecm going bad honestly
 

· Super Moderator
Joined
·
1,856 Posts
Loss of communication codes are also signs of poor connections or a damaged harness. More common on an older vehicle.
ECU failures are not common, it can happen but not very often. Just like folks run out and replace injectors for miss fires caused by other things. Injectors are another part that gets the guess replacement.
 

· Registered
08 LS AWD Summit white(SOLD), 07 Torrent FWD Black, 05 Pursuit Sedan, '16 F150 XLT Sport Blue Flame
Joined
·
92 Posts
i agree. check your battery termials, wires and see if theres maybe a break in the harness somewhere. Test your alternator too, you never know. I also had to repair the smaller ground connection that connects to the small threaded post on the ground terminal on my moms torrent.

I had similar codes in my 2016 f150 when i scanned it before i bought it, but since Ive owned it and driven it, cleaned the terminals, havent had any issues since.

do note though that even though they say the battery is good, sometimes the testers cannot always be trusted. We used a midtronics at the Canadian tire parts counter for free testing and turns out they're not even close to accurate. Midtronics would say its good, but the tester built into our hunter alignment rack would say otherwise
 
1 - 5 of 5 Posts
Top