just a tip where to look in your C4 if the Service ASR light keeps going on and off. My 93 Rosie would come on sometimes in 5 minutes and sometimes in an hour and a half, never a pattern. Stop the engine and it goes out but will return later. Common fix I read about is make sure the brake fluid is full in the reservoir . But in mine I popped out the rear wheel sensors and cleaned them. One had crap on the center part so I guessed it may not be picking up the wheel speed correctly all the time. Takes about a minute to take it out, just one 10 mm bolt and gently pry the sensor out about an inch , clean off any junk that may be stuck on there, a shot with the blow gun in the hole , push the sensor back in and tighten the bolt back up. So today went on my trip to Saskatoon and back , 216 km and the light never came on. So I think I got it fixed, simple and cost nothing.