On my 2009 RX8 R3, my ABS and DSC lights would come on sometimes. When the car was restarted, they would clear. The problem became more frequent until they appeared each time the car was driven. The problem would occur after I braked and released the pedal. Before I solved the problem, the most recent codes were c1186 and u2064. I happened to have the car in for a clutch, and my tech noticed the lights and codes. He said I need a new ABS unit. I ordered a used unit and was about to schedule an appt. to have it put in when I noticed my brake lights were not operating when the pedal was depressed. Interesting.

I ordered the part from the dealer, Switch, Stop Lamp L232-66-490A. It was a bit frothy at $52.28, but I wanted a factory part, and they had it the next morning.

I installed the switch and all is good. The brake lights work, and the ABS and DSC lights are off, and the ABS actuates.

So, if you see your ABS and DCS lights appear after the first brake actuation, try this. The diagnosis path makes sense.

Installing the switch is pretty easy. Turn the switch about a quarter turn clockwise and pull it out. The new switch only goes in oriented one way. To remove the connector, use a flathead screwdriver in the slot on the switch to push in the little white tab and push out the connector. The connector is white plastic. Remove the connector after you remove the switch from its holder.

Note that these switches have adjustable plungers. Make sure you set it to the right length. The right length for mine was about 5/8 of an inch (a guess.) When I initially put it in, my brake lights were on all the time. I had to adjust it. I think it came preset, but when I was installing it I think the length reset inadvertently. There are some videos on YouTube on how to adjust it.


I hope this helps someone, since I've been chasing the ABS/DSC light gremlin for a couple of years, intermittently. I think the brake light switch can fail intermittently until it eventually goes south.