I was very bad to my otherwise near perfect '01 C320. Here's my story.

I started getting the amber 'undervoltage consumer defective' message on the display a few weeks ago. A forum search led me to think this was an alternator or regulator problem beginning to happen. No big deal, right? Well over the past couple weeks the warning would appear infrequently and also disappear. Made a mental note to have my mechanic dump the codes and fix the problem. The car always started and ran fine. I live close to the office and bike to work most days and work at home the remainder of the time. So the car sits idle sometimes for days at a time.

OK, so I forgot all about calling the mechanic. A couple days ago, I had to take my 80+ year old parents to a Doctor visit in Boston. (Really, you don't want them driving in city traffic). On the ride in, the message appeared once, Oh, yeah, I got to call the mechanic, but, still thinking no big deal right. I'll forgo the A/C and the radio for the day.

On the ride home, life got a bit more interesting. Car started just fine. Had a couple of RED 'undervoltage consumer defective' displays appear. but, we're on the highway, not all that far from home. We should be good, right?

Got the folks home and headed back home. It's only a few more miles away. This is where the real excitement started... about 5 more displays appear and start cycling very quickly; Anti-lock brake offline, BAS ESP disabled and a couple others I cant remember. Then lost power. Dead car. Go ahead and say it; What an idiot. I said it too!

Got the car towed home. Put it on the battery charger. Thought being, I'll re-charge the battery and will be able to drive it over the the mechanic in the morning, he'll replace the alternator/regulator and that will be that. No such luck. It cranks but will not start. Looks like I'm going to need to get it towed over. I'm out of town for a couple of days so, it's going to have to wait until I get back. Dead car sitting in driveway.

Battery is charged. Reads 12volts. Engine cranks and cranks but no sign of it starting. No messages on the dash. No codes on the ODB2 scanner (but, many sensors show not started). Any ideas or quick tips? Do I need to reset something?

Mykle

btw.. I've had this car nearly ten years and it's been outstanding the whole time. This is definitely a stupid user problem.

 

You have not mentioned thinking about whether your problem is battery related .
How old is the battery?
The battery may not have sufficient voltage to operate your electrics when you are cranking.
Why not try to jump start (do it correctly) from another vehicle.

 

Have the battery properly load tested:
"Battery Voltage and State of Charge:

12.68v . . . . . . . . . . 100%
12.45v . . . . . . . . . . 75%
12.24v . . . . . . . . . . 50%
12.06v . . . . . . . . . . 25%
11.89v . . . . . . . . . . 0%"

Have the alternator & regulator checked - It needs to output about 14.2 volts reliably.

Replace the CPS (crankshaft position sensor)

 

+1 to what Glyn said.

I was getting that warning once in a while as well, no codes, and the alternator tested fine. Battery was replaced 2 years ago, but the 108 degree (F) Texas heat took it's toll on the battery. I replaced the battery and haven't had any issues since, despite the crazy heat we're having here.

 

+2 to glyn
BTW how many miles on your c320 not many 01's around here that the owner says are (outstanding) The 01 has a bad rap for being a pos
I have only had mine for 4 Years but have put way to many miles on I am at 164,600 as of tonight.

 

How is our mate Mykle going to get his car & battery to a workshop to have it tested ? .

 

Hi John,
He can do as you suggest but I worry about jump starting 2001 models. They had fragile SAM's.

Alternatively he can remove the battery or tow/flatbed. Here our dealers just collect the car on a flatbed at nominal charge as long as you use them for the repair.

 

If he's the original owner, it's free in the US. Subject to certain conditions, of course.

 

Thanks folks. I'm away from home for a couple of days, so, she's sitting in the driveway waiting for me. I'll certainly try jump starting it (using the cautions from the sticky note) when I get back. But, it was cranking fairly well; hadn't considered it might need extra help.

Battery is about 3 years old. Looks like it's holding a change. but, have not had a chance to load test it. I can haul the battery over to the local Sears store (they've been able to load test my batteries in the past). I will certainly have the alternator and regulator checked, but, the problem right now, is getting it started (to be able to make those checks).

It's not a big problem getting it over to the shop. but, I really hate having it hauled in. It's embarrassing and sort of leaves you in a very poor negotiating position. (And most of the additional bother and cost are due to self-inflicted negligence on my part).


Other comments:

I stopped bringing it to the stealerships (um, I mean dealerships) for service quite a while ago. I never got out of there for under $500, Usually there was another thousand dollars of additional services I had to say no to and it usually required a subsequent visit to repair the things they broke or neglected. I found a very nice independent Mercedes specialist in my area (Massachusetts). I'm sure there are some fine dealerships around, but, my experiences with multiple dealerships in my area was less than satisfactory.

My '01 only has about 91k mi. I do baby it, it's been very reliable and still looks brand new. A side effect of these types of forums is that you only hear from owners with problems (which is why I'm here). Makes you think they all have big problems. In my case, the car has been so reliable that I've rarely taken a wrench to it, as a result I don't actually know much about it. Of the 5 cars I own, the two Benz are the ones that haven't needed major repairs.

No, I'm not the original owner, I actually bought this car from another forum member when it was 3 month old!


Mykle

 

Why take the battery out and to a place to test when the car can give you the readings using dyno mode? I had my battery officially tested at Autozone after all the talk of dyno mode reading skepticism on this board and their tester agreed with the car's figures.

 

Mykle, What brand of battery did you replace it with 3 yrs. ago? Also, as mentioned before, go into Dyno mode and let us know what voltage it's reading.

 

Not so good here Glyn , we are 40 Km out of town. Cost would be $100s.but less than a SAM !!

 

Got back home earlier in the week looked at the dead Benz and said to myself I got to quit screwing around with this thing. Called the shop and had it towed over.

After a couple hours of head-scratching diagnosis, they asked if I had another key for the car. Thought that was weird, but, he said it would help eliminate a whole set of possible errors. Ultimately he found a blown fuse. After that it started. Replaced the alternator (the original problem) and it's all good. $612 for towing, diagnosis, replace alternator. Not entirely bade for a Benz. Thanks to all who responded.

One last thing, I tried to get it into DIAG mode, but I guess I'm not doing it right. It's key to position 1, press odometer reset 3 times and should see something on the display. Right?

 

Dyno mode is not placing the battery under a known & consistent load.

EDIT - OP pleased it's fixed!

 

Glad it is fixed.
Our 01 does not have the voltage in dyno mode. and for us you hold the reset button till you hear the beep.