So…I have a well-maintained 2015 Tahoe LTZ. About 6 months ago, the “Trailer Brake System” began intermittently throwing a warning at me during a drive (warning on, then turn off a few minutes later). Strangely, that problem seemed to disappear for about a month and then the “BIG PROBLEMS” began.

Out of nowhere, and intermittently, the car would throw a whole slew of driver assist errors. This included Stabilitrak, suspension, trailer brake, power steering (none—slightly different later, stay tuned), park assist, adaptive cruise, and possibly some others in forgetting. Took it to a trusted mechanic. First thing needed was a new battery, so swapped that. Car ran smoothly!…for a week. Then the same issues. Took it back. They determined it was a bunch of corroded connectors and wires. So, they cleaned them up. The car ran smoothly! …for a week. Then the same issues. Took it back. They determined it was more wires, some “harness,” and the trailer brake module. They replaced. The car ran smoothly! …for 450 miles. Then ALMOST the same issues (no Stabilitrak warning this time). Took it to the dealer. They said the negative wire from the battery was drawing too much power. They replaced it. Car ran smoothly! …for one day. Now I’m 450 miles from home, thousands of $ poorer, and I’m still in basically the same situation as I started in. Ugh.

The current errors displayed are suspension, trailer brake, adaptive cruise, and steering assist (at this point it will EITHER be “reduced” or none…no rhyme or reason as to which of this happens), and sometimes the park assist (the lane departure doesn’t display any warning but it also won’t work). The lights displayed IF the issues crop up are the parking brake, the ABS, and the traction control lights. With the exception of the park assist, all of the above will happen together or none of it will happen. I

t’s SUPER intermittent. Sometimes the car starts and there are zero issues. Sometimes it starts with all of the above. If that happens and I wait a 15-30 minutes and try again, it can work fine again. The only other weird things I’ve noticed are the sensor for day/night seems to not work as well when these issues are happening and the front proximity sensors seem to notice things that are not there (for example, when at a stoplight, it will display something being close when there’s nothing). These two seem things are “issues” if the above errors are present during a drive or not. No clue if this is related.

So, any ideas…??!