ABS light coming on in heavy rain?

[carys220]

I was on the motorway yesterday driving through what felt like a river with buckets being poured overhead when the ABS light came on in my Golf 1.9 TDI. I hadn't used the brakes for about 15 or 20 mins.

I've heard that heavy rain and cold temps can make this happen. Has anyone else experienced this or should I just take it to the garage?

I haven't been able to check if the light has gone off or checked the brake fluid as it hasn't stopped raining!

Any advice is greatly appreciated.

[Durrell]

Hi there! I have a 1999 Mk4 Golf 1.8 with the exact symptoms.
The abs light illuminates occasionally, and they occur only when it is either raining or very cold.
This normally happens on my way to work or on my way back home, so the next time i get into the car is like 8 - 10 hours later, and then the abs light is off.
I am still trying to find out as to what could be at fault.

[batteryman]

Possibly corrosion on the electrical connections somewhere causing a short when it gets damp with rain or dew. I'd look for corrosion at the connectors from the wheel sensors on the hubs first. Beware - I was advised by an experienced mechanic that the sensors almost always break if you try to remove them.

[Brian Holstein]

Did you ever figure this out? Same exact thing happened to me yesterday. I was driving for 20 minutes without touching the brakes, in a heavy rain, and on comes the ABS light and ESP light. How did you fix it?

[indyandy]

I would suggest that you try and get your hands on a fault code reader and see if there are any codes. If you're lucky it will give you a code to one of the wheel stations on your car.
Then that will give you a good clue as to where to start looking. An abs sensor is only a few quid and you might start replacing that on the basis that its quicker/easier to replace than actually diagnose.
The sensors work on a magnet principle....and it doesn't matter what car you have....the magnets do deteriorate with time until eventually this abs light comes on. Of cause its not just the magnet strength....its the cumulation of all the faults in the circuits which result in no pulse being detected. So in your case it could easily be a higher than normal resistance connection with a weak magnet. The rain just might be enough to tip it over the edge ...so to speak. Magnet strengths are influenced by temperature.

[Brian Holstein]

I would suggest that you try and get your hands on a fault code reader and see if there are any codes. If you're lucky it will give you a code to one of the wheel stations on your car.
Then that will give you a good clue as to where to start looking. An abs sensor is only a few quid and you might start replacing that on the basis that its quicker/easier to replace than actually diagnose.
The sensors work on a magnet principle....and it doesn't matter what car you have....the magnets do deteriorate with time until eventually this abs light comes on. Of cause its not just the magnet strength....its the cumulation of all the faults in the circuits which result in no pulse being detected. So in your case it could easily be a higher than normal resistance connection with a weak magnet. The rain just might be enough to tip it over the edge ...so to speak. Magnet strengths are influenced by temperature.

Thanks for the great info, I've been out of town the last couple weeks so I haven't done a thing about this yet, but I plan on getting a reading this week. Hopefully it will tell me which wheel. I suspect the front left wheel. I had a broken snow chain tear the wire harness in half in December. It worked fine after I replaced it, but I bet it could have damaged the sensor as well. I never knew magnet strength is influenced by temp