U0101 Code and TCM issues

[Bowser-II]

Hi Guys, my H3 DIC is showing an intermittent CEL, but the Stabilitrak and Traction Control failure message is on full time and it is indicating gear 1 only.
Shift lever requires a manual push of the solenoid to be able to shift.

Ran code check and it is returning U0101, failed communication to the Transmission Control Module.
This error indicates a bus communication failure to and from the TCM.

Work done so far:
1. checked the basic connections, nothing is loose or dangling.
2. checked the TCM, transmission, fuse box grounds, all are good.
3. checked the fuses associated with the TCM, all are good.
4. will be checking the pins (female sockets actually) on the TCM connector shortly, mainly proper battery and similar voltages, no point in testing for data using a DMM....


What else should I be checking?

Would a proper GM Scan-Tool really reveal any more information about this issue, I have to think not because if communication is lost, what data could be transmitted to the network?

 

[alrock]

That’s a good (bad) one. Honestly, haven’t heard this one before. Since you have a 2010, the TCM is a separate module from the PCM (this changed in mid-2007) so it should be easier to source/replace if necessary. About $130 on eBay for a refurb one and this guy will program it to your VIN for you. https://www.ebay.com/itm/133635631651

But I don’t have any specific troubleshooting help for you. This one’s over my head.

 

[EndeavoredH3]

If you can gain access to the technical manuals for your year you can go down the troubleshoot tree for process of elimination. Maybe an all data subscription for short term?

I’d try and help but my technical manuals for 06 h3’s. And they had the pcm/tcm in the same unit.

 

[Bowser-II]

Solved the issue.

After letting the thing sit for some time, honestly I get a little tired of working on the issues in this truck...

I'll get a help guide going for the effort that will be useful to anyone with CAN or general wiring issues. Also, if anyone comes across a U0101 issue, know that the TCM wiring diagram in the Schwartzy manual is very close but not quite the same for a 2008~2010 H3 Base model as you see in his wiring diagrams. I have it somewhat mapped out... But not fully, and I did not buy a copy of the exact schematic anywhere.

Issue was not the TCM or the CAN bus data lines but the 12v Battery wire. It had worn through because it supported the entire weight of the cable bundle running between the fuse box and the battery box where the bundle is clamped in place with the a factory tie wrap.

Fun times.

 

[Julio]

Hi Guys, my H3 DIC is showing an intermittent CEL, but the Stabilitrak and Traction Control failure message is on full time and it is indicating gear 1 only.
Shift lever requires a manual push of the solenoid to be able to shift.

Ran code check and it is returning U0101, failed communication to the Transmission Control Module.
This error indicates a bus communication failure to and from the TCM.

Work done so far:
1. checked the basic connections, nothing is loose or dangling.
2. checked the TCM, transmission, fuse box grounds, all are good.
3. checked the fuses associated with the TCM, all are good.
4. will be checking the pins (female sockets actually) on the TCM connector shortly, mainly proper battery and similar voltages, no point in testing for data using a DMM....


What else should I be checking?

Would a proper GM Scan-Tool really reveal any more information about this issue, I have to think not because if communication is lost, what data could be transmitted to the network?

Hi,
My H3T's battery was fully drained. After recharging the battery and several attempts to restart the truck, the truck was dead, solid dead. Removed the (-) battery connector and apparently the computer got a rebooted. I was able to turn on the truck but suddenly I had the message "transmission failure" and was not able to move the gear. I turn off the truck and removed both battery connectors, the (+) and (-). Then, I gave it a second try and the truck turned on perfectly, with no failure messages. Apparently, you need to disconnect both terminals to force a full computer re-load and remove any bugs (similar to your desktop reboot). Hope this helps those having a similar issue, this platform is very helpful for Hummer owners.