2009 c63. 108k. Basically stock other than updated head bolts and aesthetic mods. Daily driver.

Three weeks ago I had an EBR, ABS, ESP inoperative message on the dash. No power steering, no abs, no ESP, no cruise control. The car drove fine otherwise. It only comes up when the car hits 12 mph. It showed up two times one day and then went away. It never came back after that day so I didn’t run the codes.

A few days ago it started coming up again. Now it happens every time i hit 12 mph after a start. I drove around a couple days like this and then pulled codes.

5001 - ESP internal fault
5944 - ESP internal fault
5938 - check steering angle sensor
7266 - DTR distronic - consequential fault

I don’t get any fault messages on the dash until I hit 12 mph.

I erased all stored codes. Now I only get 5001.

Used my iCarsoft MBII scanner to monitor live data. All sensors seem to be working fine. Steering angle, wheel speed, brake switch, etc. all seem fine.

Unplugged and cleaned the ESP module contacts. No change.

Tried using my spare key. No change.

Reset the steering angle sensor. No change.

Battery is OE and a few months old. Voltage seems fine according to iCarsoft. No voltage related faults.

My conclusion is bad ESP module.

I am planning to send it to Xemodex.com for repair. Any thoughts before I spend $500 sending in the ESP module?

If someone doesn’t have a magic fix, I’ll send it in for repair on Monday and report back at the end of the week.

It’s the wheel speed sensors

I thought so too, but there are no faults for the wheel speed sensors and they are all putting out good data as far as I can tell. Any way to test them with the iCarsoft?

Try to scan it with xentry

Wheel speed sensors are $50 each and practically a maintenance item. Versus there not being many (any?) instances of the $500 ESP module going bad. Might as well replace those first.

I had to replace mine last yr!! Xmodex was a small drive for me and they opened it up as I waited, but unfortunately it was burnt, so a new one was 1600ish Canadian plus indy shop charged me 300 for programming, needs to be coded to the vin...

Oh and OP have you changed your idler pulley bearings yet?? If not, there due!! And go with a billet rebuildable aftermarket set

Yep. Changed the pulleys when I changed the battery a few months ago. Original pulleys and battery. Couldn’t believe the 10 year old battery was still working. Neither needed to be replaced but didn’t want to continue pushing my luck with the pulleys for sure.

I drove around watching the live data from the wheel speed sensors and they seem fine. Has to be the ESP module.

I went down this also and glad I had xentry. It will tell you exactly what is going on and give you data no other scan tool can provide.

Mine was front passenger wheel speed sensor.

And a few years later I got a huge esp error from changing to 16in drag wheels that no other scan tool could reset.

See what your dealer charges to scan the car or go in with the codes to get an oil change and see if they say btw you need this and that to fix your stability problem