It must be the season for it, my car is testing my patience and my wife keeps saying "told you not to get another GV!"

Anyway, I've now got the TRAC OFF constantly illuminated. It came on whilst sat at traffic lights the other day (2 minutes into a journey) and stayed on.
When I stopped, I checked temperatures and didn't feel excessive heat coming from the brakes.
Next ignition on, the light stays on from immediate start-up, so I think that eliminates overheat on the brakes switching the system off.

My next though was the wheel rotation sensors, suspecting one of them is faulty/giving back faulty/no readings so the ECU is disabling the system, does that sound plausible? In which case this weekend I'll be crawling under to try and get a multimeter reading off the rotation sensors unless somebody happens to know where all those wires feed back to in a sensible location in the engine bay?

Other than the above, are there any other areas to check that will cause the "TRAC OFF" to be on like this? (Faulty ECU is always possible, but no other functions are showing faulty)

 

1st to eliminate would be ABS sensor Andy lad

1+2

 

I thought that at first, but I'm not getting the ABS warning light coming on, this is purely just the TRAC OFF light?

 

- agreed Andy, I too would expect an ABS light in tandem
- but I have seen it where the TRAC comes on [OFF] before the ABS is fault registered

In any case, cheap & easy first in the cost menu and expensive and hard last in terms of test[s]. You know where I am next Wednesday, same rules. You are having a lot of '****le' issues coming to a head, the trouble is they are not interrelated. best of luck.

 

I have a Trac off light from day one when I bought the GV. Also I'm getting intermediate Brake light. I checked temperatures and the same as Andy, I didn't feel excessive heat coming from the brakes. I haven't looked at the problem yet, waiting for better weather.

 

I know I know silly answer but have you switched it off via emmmm switch....Silly yes...
I'll go stick my head in the Snow...

 

Thanks QinteQ, yep my thoughts too but yes probably worth going over all the obvious ones first. Hoping for calmer weather tomorrow/Sunday and I'll have a look (Blowing a hurricane out here tonight!)

Andrips, I'll feed back on what I find, might help you track (no pun intended) yours down too.

Goggs m8, yeah if only it was just pressing the button ;-) I did try toggling the button a few times to be honest just to make sure, it doesn't budge, not even a flicker.

 

The default is the TRAC system & indicator light tests as ON every time the ignition switch is turned ON, even if you turned it OFF.

 

Thanks Andy, I'm pretty sure that mine is off because of the Brake light. Looks like if I play a little bit with hand brake cable,the brake light goes off. Maybe the sensor, but will wait for warmer weather.

 

Just bringing this one back up as it's nicer weather and the other night I changed the front brake pads (oops, very low!) and noticed the sensor cog was covered in rust and not in a good shape.
Unfortunately I didn't have the time that evening to clean it up and check out the hall effect sensor (If I remember rightly), but again I'd expect this to also trigger the ABS warning if the sensor wasn't showing feedback from wheel speed, etc.

But, plan is to spend a bit of time at the weekend, clean up the cog, check the sensor (I noticed passenger side the sensor wire has ominous black eleccy tape round it, which immediately makes me think bodge job... Cos I do the same!) so that's the first one to take a look into it.

My real question though, ABS and TRAC, they both need wheel speed sensing to take place? So a fault with the wheel speed sensing would trigger both faults? (Or I guess if sensor didn't return an OK, would TRAC fail and ABS not bother until it tried to operate, then perhaps fail?)

A lot of guessing, but as QinteQ says, easy bits first, bit of cleaning and testing to do.

Andrips did you get yours sussed out?