rskinner

Recently on my 2001 C240, I occasionally get an error that says "Consumer Undervoltage Defective". The manual does not state what this means and I think it is telling me I have low voltage and should replace my battery. The stealer says to bring it in, could be the battery or alternator. If it is the battery, I'd rather replace it myself. Has anyone seen this before?

Thanks.

SUNILP

Yes I have seen it before when my battery was getting bad. Probably is the battery.

rskinner

Thanks, I guess after 4.5 years it is time to change the battery and if I still get the message I can take it in.

rskinner

Well, after 1 week in the shop I have my car back. They thought it was the voltage regulator, but ended up replacing the alternator. Thank goodness I bought the MB extended warranty. They also replaced suspension bushings, motor mounts, window regulators, valve cover gaskets, tail light wiring harness and checked the power steering. All this on a car with 82,000 miles.

raywong@hkstar.

Whenever I turn the fan to high and let the engine idle at 800rpm, the voltage will just keep dropping, and eventually it will reach below 11.6V and the display will show the "Consumer undervoltage defective" message. The only solution is to rev higher than 1000rpm or turn down the fan speed.
Is it the battery, the voltage regulator or the alternator?

LorinserCClass

which reminds me I think I need a new alternator, do you mind checking your invoice to see how much they are 'supposed' to be?

benzmodz

Consumer undervoltage means that the luxury devices are running out of power and that the fuse box is on the verge of shutting down devices which is not supposed to be possible with the engine running.

The car does not shut down in one jump. It starts off by losing things that make no difference to the car running like navigation, heater and radio (consumer) and then when things are really low it drops out things like the roof (sunroof or folding roof) until it reaches rock bottom and then the car just runs out of battery.

integlikewhoa

Its not the battery. The job of the battery is to store power. Your alt should kick out around 14v when the vechile is running. And it should also provide enough power to your vechile while it is running that you can actually take the battery out of the car and it should keep running. Most likely you have a bad Alt. It could also be the voltage regulator but not as common i would say. Also some alts have the regulator built into the alt so they both takin care of in one simple shot of replaceing the alt. IM not sure how it is on the 203s tho. have to asking someone else for that info.

rskinner

Sorry, but my invoice copy only says N/C - $0.00 . Part # 011-154-91-02-88, was only putting out 11.72 volts at 2000 rpm.

The service rep said they replaced the voltage regulator, but after more testing they wanted to replace the alternator, too.

The error would happen while idling, more frequently while the a/c was running. But after a restart the error was gone. I would guess over time the battery would run out of juice if it wasn't fixed.

Newtigger

My C240 has the same message plus the " Battery/ Alternator Visit Workshop" and at first I thought it only battery. So, I called the MB road assistance and let the guy change the batt. However, after a week the message still pops up in the dashboard. The bad thing is the car completely can't start even w/ that new batt. I tried to jump but it wont do any better.

Right now the car is at the dealership waiting to be checked on Monday. The service advsr said it could be the alternator. I am wondering how long does the alternator usually last? My c240 has only 32xxx and it's a 2001. I feel it's too soon to have the alternator be replaced.

Anybody got a comment or input?

amdeutsch

Wasn't there a post in regards to MB havings issues with the VR and the Alt? I'm still haunting my SA about it. They, MB, appearently started notifying E-class owners on this so called recall.

Newtigger

Thanks for the info. Do you happen to fing the post that has the info? I tried to search but still no luck.

I hope this is a recall cos It's really too soon to me to change the alternator for 32xxxmiles. Anyway, Does anyone know how much to change the alternator at dealership?

Thank in advance

benzmodz

I have also learned that people direct wire their batteries in conjunction with 100amp sound ampllifiers which prematurely wears out the alternator.

pookie

i have problems with my alternator. the SA says i have to wait till i get the recall notice in the mail for them to do anything about. i talked with mbusa back in april/map 2005, a month after the recall was in the news. they told me to wait for the letter as well since it will be a while to get their act together. i think they might notify people by class (i believe clk, e, and c were affected).


my problems: bad start. car will not turn on at all after turning. sometimes when the car does turn on, the car will show up with a warning 'bad alternator/battery". the damn dealer change the battery and starter twice and not once the alternator. so ridiculous.

cmbianchi

Just had the roadside guy out to my place also, checked battery voltage and did a load test on the battery, the battery passed the load test although it is 4 yrs old everything was lower than new. Suggestion was to take to the dealer for either an alt or volt regulator. Car has only 25,400 mi on it, not to thrilled about low mileage problem of this kind. Sure thought the battery was to blame.

Outland

It may be the placement of the altenator on the V6...if they get hot, they die at an accelerated rate.

Newtigger

Can somebody get verification that this prob related to the recall that other MB model has?

I am just collecting information as much as I can before the Service Advisor call me on either tomorrow or Tues

TIA