nlpamg

Hey guys,

I had service B performed on the w203 yesterday and I had them replace the battery as well. The battery was replaced 3 years ago at 45k miles and now the car is at 94k miles.

I had them replace the battery b/c during starts in the morning, the car would shut down the radio, a/c, etc. Intermittently, I would get the "Battery Alternator Visit Workshop" error.

I took it to the shop a year ago and told them this and they tested out the battery and it appeared that it was getting proper voltage.

But, this morning, I got the error message 4 times straight, consistently. It usually happens in the mornings when the car and the temperature (this is So. Cal.) is relatively cold (which is below 60 degrees).

I took the car on a very short drive and then the car for a moment said ESP unavailable and shut off the radio, but after a few seconds everything came back on.

So, I realized that I needed to check it out in dyno mode... I put the car into dyno mode and took the car for a pretty hard drive just to test it out:

When I started the car in dyno mode it read 12.5-12.6V.

At idle it jumped up to 13.4-13.5V.

Under acceleration and highway speeds, it was at 14.1-14.2V.

All those numbers seem normal. I guess my alternator is going.... Any thoughts?

Thanks.

contact148

try same thing dyno mode at idle
note voltage then turn on the headlights it should drop but come back up then the heater, seats, defroster ect load up all power items and see if the voltage comes back up

seems kinda low.....

havoc_vulture

I had the same problem a couple months ago.
I replaced my alternator and the problem was solved.
That was my experience with my alternator. Same signs as you have listed there except that I did have some under-voltage on two occasions that i put a volt meter on it. Good luck.

Xhale707

If a malfunction occurs in the charging circuit, do not immediately assume that the alternator is causing the problem first check the following items.

1. The battery cables where they connect to the battery. Make sure the connections are CLEAN and TIGHT.
2. Inspect the external alternator wiring and connections.
3. Check the drive belt condition and tension.
4. Check alternator mounting bolts for tightness
5. Run the engine and check alternator for abnormal noise.

6. use a voltmeter, check the battery voltage with the engine off. It should be at least 12.6 with a fully charged battery.

7. Start the engine and check the battery voltage again it should be 14.22 No more than 15.

If the indicated voltage reading is less or more than the specified charging voltage, have the charging system checked. The voltage regulator sometimes tends to go out. At that time just replace the whole unit


But OEM battery last's a very long time 7 years or longer.

If it's not the alternator other choices are your fuel filter when was that replaced?

Dirty or clogged Fuel injectors can cause this 2 try techron from chevron.

Also Defective spark plugs along with defective coolant temperature sensor.

But im 99.8% its the alternator or the voltage regulator.

splinter

Almost certain nlpamg uses Techron with some regularity.
Failure to do so will not prompt a "Battery Alternator Visit Workshop" warning in the MFD.

Its replacement battery is OE-specification, yes?
Our little C’s have unusually high ampere-hour requirements, not to mention being particularly finicky with all things electrical.
Had a high-end aftermarket replacement fail (in the GMC) within a week of installation. Replaced under warranty, but it’s always a PITA to call AAA at 05:30!
Don’t want to hear of you suffering a similar fate.

Curious yours registers 12.5 volts before starting and 14+ while underway; exactly as it should. I’d first suspect a marginal ground or faulty connection in the circuit, but I’m no EE. Telling that it’s throwing errors the day after yet another battery installation. Hard to pinpoint without proper DVM or SDS diagnosis, though.

Respectfully suggest load testing not only that new battery, but also its alternator.
The alternator contains diodes and a rectifier that can manifest intermittent weirdness, in addition to normally-occurring brush and armature wear.

PN is 271 154 08 02 88. ~$350.

LILBENZ230

Phil my 2005 now has 95,200 miles and is on the original battery. Here are my numbers:

Pre-start, cold: 12.2V
Idle: 13.4-13.6V
Underway: 14.1-14.2V

Those look really similar to your numbers. I have never had that warning or any of those symptoms, ever.

Glyn M Ruck

Phil - Those numbers are OK. As splinter says could be a wonky diode in the regulator/alternator but they usually work or don't.

Step one is having the battery load tested & check all connections especially ground/earth.

What codes is she storing?

Make sure you have a 100Ah battery

nlpamg

Thanks for all the help, guys!

I can't read any codes on it, and they didn't tell me if there were any codes on it when they did the Service.

They got the battery from the dealership and I would hope that it was installed properly.

Apparently, this morning, the car did it again and it felt like it was going to die. Then after 2 restarts, it was working fine.

The engine is still pulling strong. It's just the damn electrical.

I guess I'm going to just have to bite the bullet and put in a new alternator.

Are there any other parts that are worth replacing while he's in there? They said that it was a pain to get to the alternator on the M271...

Thanks.

mleskovar

Before replacing the alternator check your battery at various times to see if it's being drained...like from a seat module. Your idea of "relatively cold" Assuming you have a DVM available....
1. Check battery voltage after you stop following a good drive that would charge up the battery....should be >12.45 Volts (75% charge)
2. Check battery voltage the next morning before starting....did it drop at all?

FrankW

your alternator went dead. lol

nlpamg

so I told my shop that I found an alternator for $370 on RMEuropean and they also found the same thing for $10 less (it was a Bosch alternator).

they put it on and the car was doing the same thing. they checked on STAR and said that the car didn't take the alternator and that they have to replace the Bosch alternator they put in with a Valeo one from the dealer.

while they're at it, I'm having them replace the belt as well...

havoc_vulture

Again same thing as me.
except i did not replace my belt

Glyn M Ruck

That's wierd - The Bosch & Valeo alternators should be interchangeable. Has the Valeo alternator cured the problem?

havoc_vulture

Once i installed the Valeo it was fine and has been fine since for me.

LILBENZ230

I'll make a note of this and only buy the Valeo if/when the time comes. My car doesn't show any signs of alternator trouble @ 95,500. Even the original battery seems okay.

eesjunin

replaced my alternator with Duralast with no problems...at fraction of the costs you are mentioning
Lifetime warranty!
Bosch oly comes with 2 year

seagel1000

Incase anyone is wondering, this is the Valeo alternator i purchased. Lmtd. life time warranty on the part.

http://www.napaonline.com/Search/Det...+50044+2044109

My local NAPA had it (located on Washington Blvd & Eastern Ave in Commerce, CA) right around the corner from the Commerce Casino off the 5 freeway exiting Washington.

It was $274 and change OTD. With core refund it is coming out to $198. That is fairly low if you ask me!

tijn

had the same problem about 1 year ago. replaced alternator problem solved.

drho2004

man oh man...ive been having the same issue with my MY2005 C230k with 71k miles...on cold mornings (so.cal here) i get the no ESP warning followed by the Alternator warning, but all works well after that. Even my cruise control is fine. But it seems its my altenator going out here. dammit..
how difficult is it to do it on own? or is this something better left for a shop/dealer?

havoc_vulture

i can do mine in like an hour and a half
good luck
not too hard actually
the alternator comes out from the top

ammar_rage

I had started another post with the similar problem...my voltages are same as Phil's, if there is a problem with the alternator then there is a very good chance that the battery would prolly not get fully charged and if we are able to see the voltages around 13.5 after a good drive hints that the alternator might very well be ok...now as i do if you experience that your voltage is below 12 v the next morning, then to me it seems like the battery is just not holding the charge. My battery is over 7 years old now.

seagel1000

2 hours tops with all your tools ready.

Follow this thread for pics and steps/tools needed.

https://mbworld.org/forums/c-class-w...8l-c230-2.html

drho2004

thanks for the reply...now this is getting weird..i keep getting all kinds of weird electrical issues..i.e HUD tells me that my left blinker mirror is out, but..i physically check and its working just fine, tells me that my coolant is low i check, not its not. it does this every other day. it seems the ecu is acting up, giving me all these errors. question, how do i 'reset' the computer? unplugging the battery then reconnecting? does the dealer need to 'reformat and re-install' the software ? thanks!

bigspender101

Hey Havoc, Do you have a write up on how to replace the alternator? Ive searched and haven't come up with a good one.....

JTB007

I went to the Napa site and the don't carry the Valeo for my '05 C230 Kompressor...any suggestions fellas??