jb0190

I have an 02 C240 that gets intermittent ESP Warning Visit workshop. This error sometimes happens when I first start the car (car still in park), sometimes after driving for 10-15 min (most of the time), and sometimes not at all (rarely). To me, this sounds like a sensor going bad. I have 2 questions. I have seen many posts about this issue, but havent seen how this issue has been resolved. My first question is, does anyone have any advise on which sensor could be going out. Secondly, does anybody know if I take my car to autozone will their machine pull the code since no check engine light is on? Thanks.

Glyn M Ruck

Please pull codes - stops guessing. It could just be the steering angle sensor out of whack - if so park the car on a smooth piece of cement & turn the steering from lock to lock 5 times. This will reset the sensor

Can be speed sensor or if you get unlucky the lateral & yaw sensor or other ESP sensors under the boot carpet. See my recent post in this regard with pics & PNs

Here

https://mbworld.org/forums/c-class-w...ol-module.html

jb0190

Will my OBD II code puller do the job or will I need to visit a repair shop?

112233

Hi,

your car is from 2002, right? There was a problem with the connector of the ESP module. There was also a repair set avaliable. You can try to pull the big connector of the ESP module under the hood and clean it from oxides. The contacts are made out of aluminum.

I had a similar behaviour and it dissapears completely. Try it.

good luck

C.

jb0190

How exactly do you get that connector off the main esp unit. I'm afraid I'm gonna break it. Thanks

Glyn M Ruck

Your OBDII scanner can't analyse the ESP unit itself - need a Star or Carsoft for that. It will however tell you if a sensor is putting out garbage.

Listen to the post about the aluminium connectors. We have no experience of that in SA so I don't know what the poster is talking about - must have been a US problem. I will look at the TSB list

112233

The plug of the ESP module (under the hood where all brake lines are) is fixed with a bracket. If you open the bracket, the plug is retracted automatically. You cannot do anything wrong. In the first years of the c-class, there was a problem with oxidizing connectors, producing an ESP error in the display. The error code were different. So, thats the easiest way to clean the connector. If the error dissapears, you are fine. If not, you have to go to the dealer.

good luck

jb0190

I finally took the plug off and the top 4 connectors where the plug goes into appear to have a bit of brownish color around them. I tried to use a wire brush to clean them but can hardly get to them with the brush. Any suggestions how to clean that stuff off the connectors? Is there are type of cleaner that would work best?

112233

I used a cleaner for electronic devices.

Do you still have the error?

Glyn M Ruck

Yes - a good electronic switch cleaner would do the trick

jb0190

Yes. The error keeps coming back. I even replaced the brake light switch because I had an extra one at home. I'm starting to think its the throttle position sensor?? Or maybe a wheel speed sensor.

Glyn M Ruck

Have you downloaded fault codes yet???

jb0190

No, and I know I need to. Any idea how much the dealership will charge?

jb0190

Will any OBD2 reader pull the ESP code? I know my cheap one will not, but what if I buy a better one? If so, what do I need to look for in a new OBD2 reader? Thanks

LILBENZ230

Glyn said that an OBDII reader cannot analyze the actual ESP system. You gotta stop guessing.. it's a waste.

Glyn M Ruck

Go to any Autozone & they will download codes which will tell you if any of the sensors that feed the ESP are faulty or buy one of these at Kragen/PartsAmerica & do it yourself - $50



You need a Star or similar to diagnose the ESP itself. You need local knowledge on cost