My son in law reports that his brake and ABS warning lights came on for a few seconds then went off. The maunaul says there is a danger the rear brakes will lock up before the front and cause and unsafe condition. (Like any non ABS car!!)

It happened the day I changed the oil, so I looked at the ABS unit and filled the barely low master cylinder reservoir. When I say bareley low, it was well above the low mark, not quite to the max. We pressure bled the brakes about 10k miles ago with ATE Super Blue. I move the coolant reservoir out of the way to get at the oil filter but saw no sign of this causing a problem.

Any ideas what would cause the lights to go on?

Lou

 

If the light turns off and stays off i wouldnt be too worried about it. If the light come back on i would first check the wheel speed sensors (one on each hub). They can get dirty. They also tend to pop out of the spindle a bit because there is no fastener holding them in. Push them down and make sure they are snug against the spindle.

 

my brake and abs light have been on as long as ive owned the vihicle
the brake light flashes

and it doesnt go away

 

ahhhh, the ABS module. Chances are it **** out. Although a wheel speed sensor can be a culprit. As mentioned above, check all 4 sensors (Vag-Com) it will let you know which one it cannot communicate with. If it cannot communicate with any, they may be shot or the ABS module is damaged. I'm fairly certain that's how you'll know.

 

Thanks JONUS. I will start there if it comes back. Does a basic code reader plugged into the ODBII plug read the wheel sensor faults or do I need the VAG Com?

Lou

 

OBDII will not diagnose the wheel sensor faults, only Vag-Com will tell you what is going on

 

Thanks OD, I was afraid of that. So far the lights have not come back on.

Lou

 

I just had this happen to me yesterday, driving along and abs and the brake symbol start flashing for about 10secs. lights went away, all stops well, locked them up last night to check, abs still works.
going to vag my car tonight.

 

Also, check your CV joint boots. If they tear, the grease will fling out and in addition to causing your CV joints to fail, that grease can screw up brake-related things. Pretty sure that's happening to my car at the moment. Replacing the CV joints this weekend.

 

Fault Found:
01203 - Electrical Connection between ABS and Instrument Cluster
03-10 - No Signal - Intermittent

01203 - Electrical Connection between ABS and Instrument Cluster: Open or Short to Ground
Possible Symptoms
ABS Malfunctions
Possible Causes
Wiring between ABS and Instrument Cluster defective
Instrument Cluster defective (rare)
Possible Solutions
Check Wiring between ABS and Instrument Cluster for Short to Ground/Open Circuit
Check Instrument Cluster



01203 - Electrical Connection between ABS and Instrument Cluster: No Signal
Possible Symptoms
ABS Malfunctions
Possible Causes
Wiring between ABS and Instrument Cluster defective
ABS incorrectly coded
Instrument Cluster defective (rare)
Possible Solutions
Check Wiring between ABS and Instrument Cluster for Short to Plus
Check ABS Coding
Check Instrument Cluster