A few months ago, I noticed the "trinity" lights on my R53. ABS, low tire and hazard(?). Figured it was a bad wheel sensor, so I bought the replacements and put it on the list. I haven't had time to get around to it yet and recently I've noticed that the lights go off for a day or so then come back on. Methinks there is a wiring problem (broken/bare) wire somewhere causing this and I remember reading some time ago about this very situation.

Without ripping all the wiring apart looking for a bad spot, can someone tell me a good place to start? I seem to remember that there is one sensor in particular that is the likely suspect.

 

I'd check at the wheel speed sensor, specifically the sensor to wiring harness connection.