I just came back from the dealership after having some strange issues with my 2005 CLK 320 and they say I need to give them almost $2000 for a new engine control unit, but I am skeptical.

Excuse the long story but I feel the need to explain what happened.

I was all set to leave for a trip last night - I had just finished packing the car, and had moved the driver side seat all the way forward and folded the seat-back forward as well to put a couple of things into the back. Since I was about to leave I had turned the car on about two minutes before this to let the engine warm up a bit, so the car was running. The issues started when I went to try and move the seat back into position - I had folded the seat-back down, but when I pushed the button on the door it wouldn't go backward again, there was no sound or anything, it was like the electrical mechanism hadn't registered that the seat-back had been locked upright into place.

I was playing around with it seeing if anything was jammed under the seat etc trying to get it to go backward again, and decided to turn the car off while I read through some threads here about it, haha! I ended up getting it to work again after folding the seat-back forward and back again several times.

I thought finally I was all set to go, so I got in the car and then suddenly the car wouldn't start! It was cranking but it was like something wasn't catching and it couldn't actually start. So I got back on the forms and started to think it might be the crankshaft position sensor because it sounded exactly like this.

This morning the car did start up normally, but the check engine light was on so I took it to the dealership to have them run the codes, and the guy there told me that there were throttle valve issues and I needed a whole new engine control unit - which incidentally only they could replace and reprogram.

They said they thought the seat issue was purely coincidence but ... it was all very odd to be just a coincidence. The car was fine before the seat, and it has been driving well and no lights are on since they cleared the codes. Did I maybe flood the engine when I was trying to crank it last night that could have caused the codes to come up? I just had the car in for its bi-annual service and my indy said everything looked good so I don't want to shell out thousands for something that isn't needed now.

I am posting a screenshot of part of the code report from the dealership just in case it might be helpful - there are some other faulty CAN communication codes with things like the rear-SAM, and the control unit SAM on other pages but the guy there seemed to think the page posted below was the most important one (the highlighting was done by them).

And thank you guys so much for any info!



Throttle and Engine Control Unit codes...

 

That does seem very odd. It also does seem like a coincidence with the seat issue. The fact that it started up when cool sure sounds like a bad CPS. But it does not look like you have a bad CPS code. Do you have the car and is it running fine?

 

I doubt the seat issue has anything to do with the ECU issues. But, I see NOTHING in that diagnostic report that indicates bad ECU. You need to find another shop.

 

Fix the two "current" codes, clear the codes, then drive it and recheck.

 

Many apologies for the delayed response guys, and thank you for your comments! I ended up just getting a rental and headed out of town the next day and just got back late last week.

When I got back the car started fine, and I drove it around for a couple of days with no issue, but Friday in the middle of a right-hand turn the car just died. All of the lights came on the dash, and it was as if someone just totally cut all power. There was no weird shuddering or any sounds, it was just as if the car was suddenly off.

Luckily I was pulling into a parking lot, and after about 10 minutes it did start up again fine several times, but I had it towed to another indy shop near me and am waiting to hear what they say.

I will keep you guys posted on any updates & thanks so much again for all of your input! I really hope they don't come back saying the same thing as the dealership (fingers crossed).

 

bad CPS usually causes trouble when engine is hot and it stalls...when cooled down will restart.

 

as above, clear the codes and drive....it sounds to me like you have a bad ground wire...just dies for no reason going around corner...easiest to check and cost nothing.