ABS light came on in the rain

longdog

Member
I am new to A2s, but have been most impressed by my newly acquired 2002/3 TDI75. Today, in very heavy rain and with a fair amount of surface water on the road, the ABS light came on and the engine switched to limp mode for the first and only time in the 1000 miles I've driven the car. It cleared after about ten minutes and I did another 100 miles, also in rain, without it happening again. I wonder whether this was just a freak event or whether there is something I should be checking?
 
You have picked an inopportune time to post with regular 'activists' away at the the ADI social, response will be slow this weekend.

Sometimes I think ABS errors can be a bit random, I experienced a spate of several occurrences of the dash lighting up with the doom laden ABS warning, it went away and has not returned in five years

Advice would be to have a VCDS scan to give some idea of were to start looking. A local member may help out if you do not have VCDS.

Simple things while awaiting scan results and more expert advice. Check brake fluid level. As heavy rain seems (might be coincidence) to be involved check rain drainage channels, in particular the dangling bonnet hoses and upturned cups. The cups have been known to have pushed out of alignment.

Apart from the above I would wait and see if it reoccurs.

Andy
 
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Just the ABS warning light or did you get the triangle or stop warnings also? More than likely damp had got into some of the wiring and or sensors. Suggest you have the car scanned for error codes either with a hand held scanner or preferably with VCDS as this will tell you more . Also worth checking all the induction system for leaks, splits and broken plastic. In heavy rain the car could be sucking in water which on a diesel is bad.
 
Just the ABS warning light or did you get the triangle or stop warnings also? More than likely damp had got into some of the wiring and or sensors. Suggest you have the car scanned for error codes either with a hand held scanner or preferably with VCDS as this will tell you more . Also worth checking all the induction system for leaks, splits and broken plastic. In heavy rain the car could be sucking in water which on a diesel is bad.
Andrew - many thanks. I will check those points. I'm encouraged by the fact that you haven't had a recurrence in 5 years.
Audifan - many thanks to you too. Am I right in thinking that you aren't making any connection between the induction system and the ABS light coming on? I did get the triangle but not, I think, the stop warning. It's subsequently occurred to me that conditions were such that a wheel could have been aquaplaning and thereby confusing the ABS system. I cannot remember whether I was braking at the time but I think not.
 
Induction and ABS are separate faults. Water common to both. Water in sensors, aquaplaning etc COULD cause ABS to get confused. Water in induction or sensors can cause limp mode. ABS and traction control lights both take signals from wheel rotation usually wheel too slow ABS and too fast traction control. ABS sensors are tempermental, you try to check them and they tend to break, so try not to touch them but have a general look around all four wheel hubs to make sure nothing obvious , bare wires loose plugs lots or corrosion. If you find anything then you will have to change out any damaged part. Check the induction for leaks especially around the air filter housing as the can be easily damaged and split same with pipe work, also check air mass flow sensor as they do not last forever. Have the car scanned to see if there are any other faults and clear existing after fixing the issue. Good time to check for electrical issues before winter, many are one offs unfortunately some require repair or replacement.
 
Induction and ABS are separate faults. Water common to both. Water in sensors, aquaplaning etc COULD cause ABS to get confused. Water in induction or sensors can cause limp mode. ABS and traction control lights both take signals from wheel rotation usually wheel too slow ABS and too fast traction control. ABS sensors are tempermental, you try to check them and they tend to break, so try not to touch them but have a general look around all four wheel hubs to make sure nothing obvious , bare wires loose plugs lots or corrosion. If you find anything then you will have to change out any damaged part. Check the induction for leaks especially around the air filter housing as the can be easily damaged and split same with pipe work, also check air mass flow sensor as they do not last forever. Have the car scanned to see if there are any other faults and clear existing after fixing the issue. Good time to check for electrical issues before winter, many are one offs unfortunately some require repair or replacement.
Thanks again, Audifan. You have given me plenty to do. I think I'll start with the scan.
 
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