On my 99 CLK430 my ABS/ESP/BAS lights keep turning on after driving for like 10 minutes. Its REALLY annoying! First I replaced the stop lamp switch, didn't fix the problem. Then I took it to the dealer to get a diagnosis and alot of codes came up. Under the ESP the following codes came up:
C1504 The system is switched off. Steering angle sensor is not initialized. The rotary speed test is faulty.
C1140 N49 (steering angle sensor)
C1201 A7/7s1 (BAS Release Switch)
So then he tells me to replace the steering angle sensor and he told me it was $170 at his cost and he charged me 130 for labor. I just drove home and the lights STILL com eon. SO I call him and he says it sprobably the ESP pump and its supposed to be really expensive. I've been reading the forums and hearing about replacing the battery, could thi sbe it? My Voltage test read 11.96 Anyone have any advice on what to do next? I'd really appreciate it.
On a side note, i just bought the renntech intake to complement my eisenmann race exhaust (cant wait til I get it!)

Update: I tried to change my rear pads today and realized the right rear caliper was frozen. I will be changing this soon. Could this be the problem???

That could be the problem yes. Also consider checking out the headlight switch i just replaced my headlight switch after having the esp bas problem on and off for over a year. the headlight switch solved my problem.

Hi There,

I can second the headlamp switch, though typically, that is a 210 problem.

Sort the caliper first, but we are starting to see more and more ESP units going down on the 208's, both control unit and the hydraulic unit (attached to each other) are giving trouble. An expensive test method, but try swapping it out... could save you a lot of time if you can get your hands on one.

Hemi265