I got my 2008 H2 SUT two years ago but barely used it until this year.

I have encountered a few issues but because they are sporadic and cannot be duplicated i am at a lost at finding a solution and the local dealer is idiotic about it.
Over the last 8 months, i encountered the following symptoms:
1 - My dashboard goes off (completely off) - it happened in 4 occasions within days of each others and the issue was resolved every time by turning off the ignition for about 5-10 minutes - I was not able to replicate that behavior and has not occurred again in more than 4 months.
2 - The ABS sign lighted up in a few occasions to disappear within minutes or upon the restart of the H2. I was not able to replicate that behavior and has not occurred in about 3 months.
3 - This past month, I encountered more drastic symptoms as the Traction Control, ABS and Stabilitrac lights lighted up AND the gear dropped down to second gear and could not be shifted up or down until the vehicle was turned off and restarted a few minutes later... It happened 6 times in the past month.

I went to the local Chevrolet dealer who told me that they could run a diagnostic for $158 after which they concluded that my transmission, ABS and ECM needed to be replaced. Luckily for me they did not have a transmission tech and told me to either bring back the vehicle in 3 to 4 weeks or leave it there. Although astounded by their conclusion, I decided to bring back the vehicle to my house to avoid storage fees and to my surprise all of the lights were gone and did reappear for about a week!!! I found out that again switching off the vehicle was resolving the most of the issues. The similar behavior occurred 4 times since and most of the time, restarting the motor after a few minutes resolved it. Clearly I do not have a transmission or abs issue!!!

I got an OCDB dongle and I am able to read the error codes and reset them as needed - it is not a solution but it is clear to me that the issue is electronic and not mechanical.

Did anyone encountered a similar situation?

 

I’ve had similar issues.
Check engine light on
service stabilitrak,
traction control lights come on and occasionally
ABS and battery charging system failure light comes on display.
At times, (and this might sound crazy but it seems to happen more in warmer months/summer and hardly ever happens in the cold months) I’ll be going down the highway 65-70mph and transmission goes into neutral (not the gear shift-just the trans itself). Engine still running, I’ll slow to about 10-15 mph and it’ll slip back in gear and downshift from 2nd to 1st. I can turn engine off, sit a few seconds and start it back up and usually it’s fine again for awhile.
Other times, it may get stuck in 1st or 2nd gear and won’t change until I once again, turn engine off and restart then it’ll be fine for a while. I’ve found also if I disconnect battery for 15-20 minutes it seems to correct the issue for a longer period of time than just restarting. I’ve had it in shop 5-6 times. I’ve been told so many different codes and problems my head is spinning. Door locks won’t work right. Keyless remote won’t unlock doors. My code reader reads different codes just about every time One mechanic did get it running good for quite a while, he said there were some wires that had worn through on the frame and were shorting out and sending bad signals to the TCM n ECM. It ran fine for a couple months then soon it started doing same thing again. I’ve replaced ABS connectors, rear air suspension on both sides. It ran fine this past winter and the first day of warm weather it resurfaced and I was back at square 1... another mechanic tells me to replace the TCM and possibly the ECM. It’s definitely an electrical issue and not mechanical tho this prolonged electrical issue may cause more serious mechanical issues. My battery charging system failure light flashes on quite a bit. I’m gonna try and replace my battery and check alternator then take steps after that if that does no good.
Its so frustrating it’s ridivulius at times. Please lemme know if you found any remedies. I love my H2 and plan on keeping it for years to come

 

The problem is related to the harness. there are diverse location where the harness my get damaged (pinched or cut) and the messages you get are an indication that there is a short in the harness. I would start by looking at the connectors on the wheel sensors... and then from them following the harness legs back to the ECU. The issue is not in any of the systems but the harness i your culprit in 90% of the cases. You could have a bad ECU but if after a reset you do not have the issue for a while, it is unlikely to be the problem.

The issue occurring in humid months point to a short created by a non insulated contact - hence checking the sensor connections and in particular the speed indicators sensors on the wheels - if they read in an inconsistent way, the ECU will trigger a safe mode event shutting down the transmission in default second gear...

 

Thanks. Ironically, the night after your reply, the rear left wheel sensor went blank (--) and again, the safe mode shut it down to second gear. I disconnected battery for bout 30 min, and all was good again. i'll check the sensors and work backward from there...I had the front sensors replaced awhile back. Its frustrating as h#ll and i appreciate your help. I'll post later when i run these checks.