when I started my C4 earlier today, all the red indicator lights in the tach would appear and disappear as normal after a few seconds. however, after i drove the car for a few feet, I hear a brief and weak howling sound and then the ABS, AWD, and [!] warning lights would illuminate. I stopped and shut down the engine. After I restarted the car, the lights disappeared. however, the three warning lights reappeared when i drove the car for a few feet. Luckily, I was still at home, so I quickly searched Rennlist and identified several potential causes.

After my research, I suspect that the ABS pump has failed, resulting in the howling sound. In addition, I removed the ABS relay (R34?) and noted that it was dated 1990 (the year of the car make) and it seems to be broken as something rattled inside the relay when I shook it. I checked the ABS connectors and they looked clean and uncorroded.

Subsequently, I started the car again and the lights did not appear. However, the ABS system did not operate as the tires skidded after I intentionally conducted several brake testing at slow speed.

so, from the information i've gathered on rennlist and my own tests, I think the ABS pump has given up, along with the relay
Any other hardware I should check?

 

I have the hydro abs unit if you need it .
Elliot

 

Jeff - get AF to rebuild for you. Takes less than a day.

 

hi-- i replaced my pump with a used one a year or so back but would love to have a spare----. who does the rebuilds on these???? thanks---tom