Instrument clustter or ecu problem - PeachParts Mercedes-Benz Forum

#1 03-01-2003, 07:44 AM

I just spent $1500can($1000us) yesterday to have the b service and all the brake pads and rear rotors replaced. On my way home on the highway the check engine light, check oil light all came on. I also lost the tachometer. The trucks continues to drive ok. When I got home everything is fine when I stop and restarted the car. I check the dispstick and there is fresh oil. What's up? Instrument clustter or ecu problem? Ground fault problem? Moisture? I wonder if a code will be set at all. Will bring it back to the dealer ,the n th time in 3 months, sometime next week. Any suggestion to take along. Love the truck, just wish the gremlins will leave the truck alone.

"M class owner are a confused bunch"

tabo · #2 03-01-2003, 10:09 AM

Will they hold responsiblity for the check engine light cuz they caused it? but they can also say its not there problem and they didn't have anything to do with it? or it could be just bad timing, to reset it just unplug the battery for 20 secs, if it pops up again than you're gonna need a ob2 scanner!

Gilly · #3 03-01-2003, 04:46 PM

What year is the truck?
It sounds pretty strange. I'd hope a fault code is stored due to the check engine light, but if there are no codes anywhere (like for the check engine light especially) I would assume a problem with the cluster. How long after you left the dealer did this occur? How many miles on the truck?
I'd also check the oil after leaving it sit overnight, it should be in the middle of the operating range. But it seems strange to have the oil warning and check engine light come on at the same time (the low oil warning shouldn't make the check engine light come on) and also have the tach quit, all at the same time.

Gilly

#4 03-01-2003, 07:26 PM

I have 130000km on my truck and this happened 20 minutes after I left the dealer. The reason why I think a code may not have been registered because the MIL did not stay on although I was told by my ford tech friend that a code may be stored in odbII even if the MIL did not stay lit. I know I have already generated quite a bit traffic on the forum in the last few days, can I ask one more question? Where is the ventilation blower for the fuse box/ecu compartment? I have this chirping noise at start up during cold weather and from what I read this is due to the fuse box/ecu ventialtion blower and someone said something about squirting some silicon on the blower axle to get rid of the noise. Thanks
Ken

Gilly · #5 03-01-2003, 09:33 PM

The module box fan is waaaaayyy down in the bottom of the module box (the module box is basically the fuse box, drivers side behind the headlight). You need to disconnect the battery, remove the fuse box lid, and unscrew and remove the rear cover of the fusebox. Then a few more screws need to be removed that is holding down the fuse panel. Underneath the fuse panel is the AAM you've probably heard mentioned before. This is all pulled up out of the box, and under the tangle of wires is the small blower, it is usually held down with 1 screw and some molded-in clips. Usually it comes out nice enough, but can be a bit of a puzzle to properly reinstall.
Have a fender cover or some old bath towels to protect the fender from scratches, as the guts of the fusebox usually has to be layed down to the fender side.
I know the blower is quite expensive for it's size, but you may want to think about just replacing it, IMHO.

Gilly

#6 03-04-2003, 09:24 AM

They scanned the codes. They found a transponder code which has somehting to do with the key and that won't explain the tachometer malfunction. The other code they found was a 4ets CAN communiaction fault and they don't feel that is the problem either. They have cleared all the code and said we have to wait ot see if it happens again. My suspicion was there was a problem with the CAN bus in general. I saw the dealer cleaning the engine compartment after servicing each vehicle with a spray wand( ? steam cleaning) and I wondered if moisture got inot the electronics and this is the the coldest March in Ontario Canada in the last 100 year(honest, coldest march in 100 years).

Gilly · #7 03-04-2003, 09:59 AM

A CAN fault would sound logical to me, given the circumstances. I would more suspect a control module "crashing" the CAN, as we put it. The only problem with the theory is that if the CAN crashed, you would have a CAN bus fault on all the modules on the CAN bus, not just the ETS control module. Stranger things have happened though. The truck has been fine now?

Gilly

#8 03-04-2003, 12:06 PM

It's running fine now. Will see what happen.

#9 03-05-2003, 10:43 AM

It acted up again. Same symptoms. This time multiple CAN communication fault recorded including the engine control and aam communiaction fault to the CAN. Now they have to figure out how to fix it.

#10 03-06-2003, 08:58 AM

After mucking around for one whole day, they couldn't find anything. They did service the ground behind the left headlamp which I have heard in other mailing list may lead to erratic control module problems.