make sure the bulbs are in correctly. gona have to start tracking the power and see where it stops.

 

Update: Fuse ABS Valve (#5 20 amps) have no power with ignition on. Fuse it self are OK. Don't know if the fuse should have power in ignition on - some one that knows? Also have a question if the relay can set the ABS and ASR light on? (marked yellow on pic).

 

After a shop scanned with a Tech II on my Camaro 1997 with ABS/ASR lights on and no brake light, I came up with 3 errors C1293, C1291 and C1292. I didn't got any fault codes with my OBD-scanner - you need a GM Tech II to go deep in to the system. The shop also hot wired the brake light connector and lights turned on.

Strange, since I already had checked the brake light switch and it was OK. Back home I disconnected the brake light switch and measured it again. I noticed that it worked even this time, BUT there was a minor resistant of ohm. I took the bright light switch apart (easy to do). And lifted up the two metal parts inside. Noticed they had oxide on their points. Cleaned with sand paper and measured again, no loss of ohm and volt passed thru without any problem. Connected the brake light switch to the car and brake lights worked. All it was to messed up was some oxide on the points. No cost to repair except for the Tech II scan.

And guess why the ASB/ASR was on even after replaced the front wheel sensor - well it's the brake light switch that give a signal to the Electronic Brake Control Module (EBCM) to turn of the ABS/ASR light on the dash board after a sensor replacement! Since my brake light switch didn't work it was no signal and the ABS/ASR light therefore was still on.

Some pictures that I hope will explain the work and can help others with same problem.



Brake light switch are located under the drivers dash panel on the brake. Remove the two panels under the steering wheel and you will be able to see it.



Remove the connection with the two wirings by push the clip with a screw driver and pull the connection away from the brake light switcher. Rotate the brake light switch counter clock wise to turn it of f the plastic part mounted on the brake bar.



Inside the brake light switch. Easy to open.



This is the tow points after cleaned from oxide.



Measuring in ohm and millivolts to verify that break points works and open/close the volts.


On this video you can see how the switch works.

 

good info, great writeup.