Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner

U1064

29K views 5 replies 6 participants last post by  Hastingsdenali 
#1 ·
Hi. Great forum.

I've searched and can't find any type of resolution for a U1064 code. I'm hoping someone can help.

My brother brought his TB to me with some issues: poor idle and sometimes not starting. He had a P0106, P0455, P0506, P2119 and U1064. I replaced the ignition switch, gas cap and cleaned the throttle body. He told me that it was running and idling much better.

However, I received a call today that the security light has flashed a few times and now the car will not crank. The electronics seems to be going crazy.

I'm going to scan the car this evening and expect to see the U1064 code again - Body control module/loss of communication with DIM. Any ideas ?

Thanks for any input.
 
#4 ·
Check Engine Light & codes

I'm hoping to ignite the conversation again concerning these codes. My check engine came on several months ago (cold weather). It came on while driving, and went off the next day (i don't remember if it didn't come back on when I started it, but it seems maybe it came on, and went off while driving).

It's not been on since.

Last week, the check engine light came on, and again was on for only the 1 day. It has since come back on, and now it's been on for 4 days.

I took it to Advance Auto and they read the following codes:

U1000 Data Link Connection Error (Class 2)
U1064 ABS Lost Communication - Cam Position Sensor
C0455 ABS Steering wheel angle sensor
C0131 ABS ABS/TCS System Pressure Circuit
C0244 ABS Pulse Width Modulation
U1016 ABS Lost Communications ECM/PCM/VCM
U1026 Loss of Class 2 Comm
P0106 Map Sensor

It seems rather odd to me that all these codes are coming in all at once and at the same time. I asked the rep at Advance Auto if it was possible that one or two codes could be triggering multiple, and it was suggested to me that it is possible that could happen. The rep thought it was important that I focus on the U codes first.

Can anyone tell me anything, give me direction on where to start, and I love photos (detailed), so if you've replaced any of these sensors, and can show me pictures of where to locate them (under the hood) and how to replace them, I'd be greatly appreciative.

Thank you!
 
#5 ·
These are nearly impossible to fix when they happen this way!

My short history.. I was an ASE and GM certified tech up until 2008. I worked on everything on GM cars and some trucks.. I have had lots of experience with U codes.

Basically every module in the vehicle has to talk to each other. If they aren't able to talk to each other they can't pass messages along to who they need to talk to. Class 2 is the communication system. This is a single wire communication system. What your codes are telling me is that you are having a problem with the PCM, or you are having a problem with the EBTCM, or you have a break or loose connection in the class 2 communication wire between those 2 modules. In my opinion, you are not going to be able to find the problem unless it happens more often and for a longer period of time. Also the "guy" at the parts store is correct, DO NOT change any parts on the vehicle until you fix what is causing the U codes! This is as specific as I can get. I have been out of the game for quite a while.

I hope this helps.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top