W203 C320 2001 No Electrical Power

[gbjeppm]

All,

This is a strange one, that perhaps somebody has an idea on.

We have a 2001 W203 C320, and this morning my dad went to start it, and nothing happened absolutely dead. So he opened the door with the skeleton key, no power to instrument cluster, courtesy lights absolutely dead.

The battery was new 3 months ago, (For additional info this car has in the past had a battery drain problem from COMAND which has been resolved, personally I don't think this is relevant)

Anyway, he put the car on the trickle charger, and within 2 seconds everything sprang to life, alarm went off, lights on, and started first time with the key, which suggests to me that there was no issue with the battery.

Any ideas welcome?

[Diesel Benz]

Sounds really strange but if the battery was OK, what difference would the charger have made? Or perhaps it was just a coincidence that the car woke up at the time the charger was connected?:confused:

Perhaps the battery was "just on the limit". Are you sure there was no consumers left on, parking lights or similar?

[gbjeppm]

Are you sure there was no consumers left on, parking lights or similar?

Well my mother, the last one to drive the car claims not, but she may have left something on inadvertently.;)

Anyway, maybe this is relevant, the reason the battery was changed is that a couple of times it would not start (for no apparent reason), we assumed it was because the battery was on the limit, and up to now the new battery had solved the problem.

It has been checked over recently and we know that there is no drain on the system, when the car is switched off correctly.

[television]

Many new batteries, mainly house names and not top brands can get what is known as a high resistance cell, what happens as long as you are use the car every day, all is fine, park up for 2 days and the battery is dead.

An easy check is an ammeter in series to make sure there is no drain beyond 30m/a
I have had fights with Halfords before now when they use their magic tester that shows them to be good, when they are bad.

Lucas official outlets use battery testers that do work, and the same for other good names

[gbjeppm]

The battery is a unipart, if that helps.

[television]

The battery is a unipart, if that helps.

well as I said if the battery is flat after 2 days and nothing leaking then it is faulty.
I had 3 in 6 weeks from Halfords, the 4th one went after they gave me a Lucas, ths lasted 2½ years when it also failed, the Lucas replacement has now been on the car for 2 years.

The high resistance syndrome has the effect that while the battery is charged to max, its OK, leave it for one or two cold nights and its dead
Sadly I had to block the doorway into Halfords before they would do anything

[television]

Let me add here, that a boot lamp on will stop the car from starting after 2 days

[Diesel Benz]

Let me add here, that a boot lamp on will stop the car from starting after 2 days

Is the boot lamp one that remains on if left on? I haven't checked from my own cars but most consumers, like radio, get automatically switched off after some time (20 to 30 minutes) if left on. The headlights and parking lights cannot be turned off automatically but there is a reminder and unlikely these were left on. I'm just wondering which consumers could be left on?

I understood that the quiescent current had been measured. I guess there would still be an option that some devices do not get to sleep at random.

[television]

Is the boot lamp one that remains on if left on? I haven't checked from my own cars but most consumers, like radio, get automatically switched off after some time (20 to 30 minutes) if left on. The headlights and parking lights cannot be turned off automatically but there is a reminder and unlikely these were left on. I'm just wondering which consumers could be left on?

I understood that the quiescent current had been measured. I guess there would still be an option that some devices do not get to sleep at random.

Boot lamps are subject to a lot of abuse from being knocked when loading, and striker plates get knocked off of bent
Not all cars have auto circuits that turn them off, on the cars that go to sleep the quiescent current is higher. My SL if not used for 5-6 days turns of all of the consumers until the battery has picked up a little, I am lucky as I have 2 batteries

[gbjeppm]

Update:

OK car eventually taken into Sterling of Worcester, who have diagnosed that the Fan on the COMAND unit is never shutting down even though it should, which is the same problem that the car had over a year ago, which was fixed by the dealer when my father bought it.

So I was very wrong earlier when I said that there was no drain on the system:o

It is no longer under warranty and has been fine for 18 months or so.

They have suggested that the COMAND unit needs to be looked at.

Any ideas, I saw this post a few days ago http://www.mbclub.co.uk/forums/showthread.php?t=44240

Has anybody ever used this service before? I would really like advice from anybody, but Alfie/Richard/ Television spring to mind as very knowledgeable in this area, before proceeding to get this resolved.

[television]

I have the same fault on my car in that the command does not go to sleep,so I fitted my own timer that shuts it down after 20 mins.

I saw somewhere here in the last couple of day that there is now a repair service for the Command's

[gbjeppm]

I have the same fault on my car in that the command does not go to sleep,so I fitted my own timer that shuts it down after 20 mins.

I saw somewhere here in the last couple of day that there is now a repair service for the Command's

Malcolm, thanks for that, can you expand on the Timer solution, sounds interesting?

The service for comand you mention I reference in my previous post, it looks like Bosch/Blaupunkt, would be interested to know if anybody has used it. I will give them a call tomorrow though anyway.

[gbjeppm]

Ok Further Update:

Comand was a problem, not the only problem, memory seat controller, and OCP were all also draining the battery, in all a draw of about 3000milliamps. (£700 parts and fitted, not cheap form Mercedes)

Mercedes like the draw to be less than 35milliamps, so Tracker (unused) and an aftermarket Sony phone system we did not know we had, was also disconnected, bringing the draw down to 20 milliamps, and so far so good.

Changing the OCP also seems to have fixed the COMAND draw.

Will update further with progress.

[television]

Ok Further Update:

Comand was a problem, not the only problem, memory seat controller, and OCP were all also draining the battery, in all a draw of about 3000milliamps. (£700 parts and fitted, not cheap form Mercedes)

Mercedes like the draw to be less than 35milliamps, so Tracker (unused) and an aftermarket Sony phone system we did not know we had, was also disconnected, bringing the draw down to 20 milliamps, and so far so good.

Changing the OCP also seems to have fixed the COMAND draw.

Will update further with progress.
What is the OCP my head is blank today

[Diesel Benz]

What is the OCP my head is blank today

I'm guessing OCP would be the Overhead Control Panel, the one at the centre rear mirror area.

[gbjeppm]

I'm guessing OCP would be the Overhead Control Panel, the one at the centre rear mirror area.

Yes confirmed, quite a common fault on the W203 apparently.

[television]

I'm guessing OCP would be the Overhead Control Panel, the one at the centre rear mirror area.


Thanks so much, and yes these do give problems, I cant see the connection to the Comand though

[gbjeppm]

Malcolm, I found this within this thread from MIRO.

It suggests that there is a link between Comand and the OCP.

http://www.mbclub.co.uk/forums/showthread.php?t=41371

For the record - things which can stay awake and drain the battery (any car)
-------------------------------------------------------------------
- front sam
- rear sam
- igntion switch
- seat controller
- overhead controller panel (OCP)
- door controller
- seat adjustment panel (stuck button)
- COMAND unit (if the OCP is stuck)
- COMAND - software update needed
- TV (if the OCP is stuck)
- TV - will not respond to CAN any more
- Phone module (old software)
- Audio gateway (early W211)

The CAN junction points are in the door well and under the cluster so you dont even need to dismantle the car. All you do is break open the two pin connection for hidden modules.

All of this information is in WIS - the workshop system.

[television]

Malcolm, I found this within this thread from MIRO.

It suggests that there is a link between Comand and the OCP.

http://www.mbclub.co.uk/forums/showthread.php?t=41371

For the record - things which can stay awake and drain the battery (any car)
-------------------------------------------------------------------
- front sam
- rear sam
- igntion switch
- seat controller
- overhead controller panel (OCP)
- door controller
- seat adjustment panel (stuck button)
- COMAND unit (if the OCP is stuck)
- COMAND - software update needed
- TV (if the OCP is stuck)
- TV - will not respond to CAN any more
- Phone module (old software)
- Audio gateway (early W211)

The CAN junction points are in the door well and under the cluster so you dont even need to dismantle the car. All you do is break open the two pin connection for hidden modules.

All of this information is in WIS - the workshop system.

Thank you and I have made a note of it all

[amith]

Hi guys.
I have a C200Komp w203
I was searching the net for a solution as I am having a draining battery problem too. If i leave the car at home for 2 days, it drains the battery. Sent it to the dealer and they found the light module, sunroof module and the key switch faulty. They cleared the faults, re-initialised the sunroof module and only the key switch seems to be faulty now. According to them, the start switch is using current when the car is locked and at rest. The part that needs to be changed, costs aprox 900 pounds here as we have 100% duty on spare parts. I cannot buy it from abroad as other dealers will not sell this part to me. I would like to know if anyone thinks it is worth spending the money and getting it changed or it can be something else causing problem? My car does nt have command system, i think we all have electric seats on w203, btw i tried to unplug my electric seats as some ppl have had problems with them but it doesn't seem to solve the problem on my car. Also changed the battery to a new one, removed all electronic stuffs that did not come with the car like aftermarket HID, Amplifiers, Handsfree kit, talking module etc.. Hope you ppl can help or share some tests that i can run to detect the problem. I love this car but i'm soon gonna burn it bcuz it is is extremely annoying.

Thanks in advance

[television]

This all depends on what the drain is. I have never heard of the ign switch doing this, but it could be possible as it is in the wake up circuit

What is the leak in milli amps

[Diesel Benz]

I would agree with the above. I bet if the dealer changed the ignition switch, they would come and tell "by the way, the OCP unit was also bad", or what ever the other part was. The earlier post shows nicely which devices are connect (and then candidates for the issue).

The dealer probably concluded based on the fault codes without interpreting those too much.

[amith]

Hi guys
The dealer highlited that it is the EIS causing problem which i think in simple words is the ignition switch. I managed to get a new one from abroad and the dealer ordered a green key to start the car.
The new problem now is that they cannot code the EIS to this car, they ordered a 2nd green key thinking that it was faulty but even this one doesn't work. What according to you guys can prevent the EIS from being coded? One of you guys were right, I have been asked to change the OCP. Can i plug an OCP from another car or simply disconnect mine and see what happens?

I also have a BAS warning on my cluster, do u know what can be causing it and how to repair it? Some ppl say it's a Stop Lamp Switch that is damaged? Can anyone tell me whether they got similar problems and can I order the stop lamp, change it myself??

Cheers,

@mith

[television]

The brake light switch can put the BAS lamp on, and stop the car starting on some cars, but not on the 203 as far as I know