Hummer h3 2009 model with 150,000 km shows a message "TRACTION FAILED,SERVICE STAB SYS"...This message doesnt show up everytime but rarely and when this msg comes None of my brake lights work.What must be the issue?
there are many causes. Take it to a shop and have them run a diagnostic scan.
You said it rarely shows up, how often is it? Is this an intermittent issue? When it comes on, do you notice any driveability issues (aside from the brake lights not coming on)? If the message is still on, the first thing I would do is scan the whole vehicle (full system scan where each module is scanned) and see what fault codes you are getting. Another thing worth trying - and it sounds silly - but let’s eliminate the low hanging fruit and that is load test your battery and make it is OK as well as confirm you have good solid + and - terminal connection between the battery and the cables. Make sure it is clean and also not loose (need a tight connection). Some of those Hummers had weak terminal connections to battery and that caused all sorts of electrical gremlins. Try those and let us know what happens.
Also, see here:
It come maybe twice a month but stays for a week or so...No driveable issues are noted other than brakelights not working...........Should i consider replacing my brake light switch?