Hi. I have a 2002 E320 that just turned 79,000 miles and on my way home just now my BAS/ESP and ABS light just came on. I cant turn the ESP off like I use to. Also it just comes on and off occasionally. Any ideas?

 

Check alternator output and battery charge,if it drops below a set voltage about 10 volts those warnings will come on.
If not that, it is the brake switch.diy on w210 section benzworld.org diy area.Get the switch from the dealer.
you can test the switch,but for 20 bucks and having to get in there to remove it you might as well replace it.
Start by the voltage test first. then the switch,which by your symptoms sounds like the issue.Check battery charge with a multimeter about 6bucks at harborfreightools.
If the brake switch it takes about 30 minutes to install if you follow directions.

 

Thank you OHLORD. I dont think it could be the alternator because I replaced that 1 year ago. I will try the test thoue. I did notice after you posted OHLORD that I do have a rear brake light out. So I take it that could be the issue?

 

Quote: I cant turn the ESP off like I use to.

So the light in the ESP switch doesn't illuminate when you press it. Note: When the light is ON it means that the system has been disabled.

Does the ABS etc warning light illuminate immediately after an ignition off/on or only after you have driven the car a short distance.

What is the voltage measured at the battery with ignition off (circa 13v), ignition on (circa 13v) and with the engine running (circa 14v). OK?

Quote: Also it just comes on and off occasionally. Do you refer to the switch warning light or the dash warning light. Please clarify.

I suspect that you battery / alternator are not in good shape but this will be confirmed by the voltage check.

Stuart

 

The light comes on once in a while. I drove it today and it did not come on at all. When it is on I cant push the ESP! button and disable the traction control.

 

Ok so it has been a week now and the lights have not came on at all. I still have my apt on Wednesday. Should I stll take it in?

 

Good question.

The warning lights wouldn't have come on unless something was wrong!
Sometimes warning lights are activated by a transient condition.
Two good examples of such a situation impacting different systems are:
Engine. Use of max acceleration up to the limiter whilst using Tiptronic.
This can set CEL but if light is reset then the light doesn't come back on again. Some consider that the light came on in error but not so.
Basically something was incorrect during this unusual run (unless you are on a track!). Usually MAF getting towards end of life.

ABS etc. This is usually caused by a low voltage supply due to a battery that is beginning to fail especially whilst cranking after the main (bootup) ABS system checks have been completed.
The system is PURPOSELY made inactive if voltage drops since the output from the ECU can't be guaranteed and it is possible that some inappropriate signal / signals could be generated with dire results.

So how old is the battery?
If its over 3 years I guess it is showing the first signs of end of life.
It may well work OK for a further 12 months if the car is garaged and does some moderate daily runs etc but of course it will die UNEXPECTEDLY at the WORST possible moment and in particular if its cold, wet or dark!!!

Get the garage to measure the battery voltage with the engine OFF and several consumers on e.g. headlamps.. If the voltage goes below 12.5 when cranking (trying to start) my position would be that the battery is on the way out.

With the engine running it should be circa 14.5v.

Yes it is worth going to the garage although more cost effective to DIY. They should also check the ECU for stored codes that may point to alternative issues.

Of course it could be 101 other things e.g. loose connection, speeds transducer dirty, brake light switch intermittent but these usually reoccur after a reset. etc etc.

Good luck. Let us know the outcome.

Stuart

 

Thanks you very much for the response. I would (DIY) but I dont have a code scanner. It goes in the shop Wednesday(I hope it is nothing to serious considering we have to travel the next morning for Thanksgiving) the shop said they can figure it out in a day by running it threw a scanner. I will let you know how it turns out.

 

Hope they don't change a load of parts without cause just because no code is set.

Suggest you get them to advise you before they spend LOTS of money!

Good luck.

Stuart

 

OK It is now official. Everything happens for a reason. I went to the shop dropped the car off. The shop said nothing wrong. No codes found. I asked if I could take it home? The shop said no. I said why? They said yuo need 4 new tires. We went out looked at it on the lift and there wear all on the inside and the rear tires where going also. The mechanic asked my wife"Did you not feel any change in the car at all? This is dangerious and the tires could of blown out and you need to keep on top something like this" I dont blame him for saying that. Sheis the only one who drives it daily. She drives only 80 miles a week! and the car is only out from April to end of Nov. It has 79,000 miles (2002 E320) So the car is in the shop untill Tuesday (4New Tires on the way). Something serious could of happined. Everything happens for a reason.