Jump Started C280 yields ASR, limp home mode
 

Left the dome light on overnight, jump started my wifes '95 C280, and now it looks like i'm gonna drop about $4K. I've got ASR light and limp-home mode. The indy changed the OVR, then started getting codes. He says we might need new DM AND ASR can. He says to have the dealer swap parts till it works. The dealer says that without an appointment, I might get in sometime this year.

Please, techs give me a glimmer of hope!

Check the fuses under the cover that is on the passenger side of the under hood area.

Check the OVP fuse!! OVP = Overvolt Protection Relay.

Do a SEARCH (top right hand corner of page), and type in OVP... these relays are commonly faulty on this engine. Also many times a jump start can cause them to go bad (or simply blow the fuse).

The part is only about $50 and you can install it yourself in 2 minutes... very easy. You can purchase it on this website (FASTLANE / PARTSSHOP), for a very good deal.

Open the hood of the car:
http://www.a-p-group.com/cklasse/Engine2.JPG
In the top left part of the picture, there is a panel (just behind coolant reservoir) which covers the car's computer and sensitive electronic equipment. Pull up this panel.

This is a picture under that panel. In the lower right hand corner is labeled OVP in yellow (hard to see). It is a metal relay with a plastic fuse cover on top. Check these fuses first. If your OVP hasn't ever been replaced, I'd replace it without a doubt.
[img]//www.a-p-group.com/cklasse/Ecu.jpg[/img]

Good luck... I hope this will be the solution to your problem. (Also OVP causes NO warm starts... engine turns when engine is warm, but does not start).

Keep us posted!

C280 ASR + Limp + Changed OVP
 

Benzmac and David, thanks so much for your quick replies! The independent shop changed the overvoltage protection relay and fuse, they said that before the change the computer wouldn't give them codes. From the indy's notes I read that Scantool states EA/CC/ISC control unit is faulty. They then checked wiring harness insulation and found no problems. (i was impressed because i learned from you guys that this could be a problem). The notes also say resistance at DM can (2,200)and ASR can(1,510) are out of spec. Dealer now says he can squeeze me in next wednesday. One can or the other I could swallow, but if I gotta do both, maybe i'll just drive it limp.

95 C280 71K
93 Range Rover Classic 135K

David, good pics - now can you tell me what 1, 2, 3, 4 and 5 are. The 240D and 300D look better everytime I lift this cover onthe E320 :):).
thanks

Oh i forget... I asked what they were one time....

I think one is the ECU, one is the Cruise Control... and I forget what the other is... maybe EFI perhaps!

anyone have similar pictures for a W124 E-class ??
 

Please post them here, or start another thread.
Thanks

This thread I started shows the OVP on a 190E

The W124 car is very similar to this under the bonnet... only with more space!

Here it is:
http://www.peachparts.com/shopforum/tech-help/42091-car-pinking-these-fuel-octane-adjuster-pics.html?highlight=ovp

OVP fuse replaced -- all fixed !!
 

Turns out all that needed replacement is the OVP FUSE -- the OVP relay itself seems fine.

On a 300CE (W124), the OVP is located (along with other electrical controls) in a compartment behind the battery. Its covered by a black plastic shroud -- lift this off to reveal the OVP relay.

Its a beige relay, with a clear flip-up fuse cover.

Picture of the OVP relay below

http://www.imagestation.com/picture/...0/fd6872e3.jpg