2001 C240 [ W203 ] CANBUS draining battery?
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I had the same problem with my '01 C 320. I followed these simple instructions I found on another forum and it did the trick. Both modules work great and it cost less than $5. Now if i could only get my tele-aid module bypassed life would be perfect. Anyway here is the link to show you how to fix your problem.
http://www.benzworld.org/forums/w203...ower-seat.html
The reason so many Japanese cars are still on the road is because they don't have reliability problems like this. This is a known failure that's been ongoing since the model was introduced in 2001. [QUOTE=mbmastertech;3489754].Electronic parts are very complicated especially on a mercedes.QUOTE]
Other makes have more electronics than a Mercedes and don't have near the same volume of problems. Electronics are electronics, one isn't 'more complicated' than another unless the engineers don't know what they're doing. This is the 21st century, electronics are easily made reliable.
This is the attitude that is will eventually put MB out of business. What people 'expect' is for cars not to break repeatedly for the same thing. But when they do, they want an honest and fair repair. It should cost no more to replace a battery in a Hyundai than a Mercedes. But it does, and big time. The notion that because a car costs more to purchase then it will cost more labor to repair is a myth perpetrated by high end car manufacturers at the expense of the consumer. There is no logic in it. People are figuring that out and buying more Japanese cars as a result. Eventually the Japanese will duplicate the ride/feel/smell/looks etc. of Mercedes and Mercedes will be out of a job.
The Best of Mercedes & AMG
To be fair, the early C class is not your average/expected Mercedes build quality. Mercedes' initial attempt at a high volume passenger car was not successful from a reliability standpoint. But you would have to be extremely prejudiced to say the Japanese brands don't consistently have significantly better quality and reliability than Mercedes. I've owned both and know the difference.
The perception of quality and the definition of quality can only be determined by the customer.
Mercedes can not define quality.
Mercedes can listen to the customer define qualilty in engineering terms based on the how well MB listens to the customer, and produces a product that will consistantly deliver what the customer wants.
Example
- The customer wants the battery to stay charged
- The customer does not want to spend excessive time in the dealer for repairs.
And the list goes on.
I have a E500 2003 that I bought new. For the $70G's I thought I was getting a "quality" car. For me quality means only wear / tear items. (oil filters plugs belts etc). Warranty repairs should be almost non-existant.
However in 80,000 miles I have had ignition key failure, door locks, ball joints, total SBC brake failure, air springs and the list goes on.
Granted the car still drives like a new car because I repair with only MB parts each item. But the time in the dealer for service is excessive and cost is what I would consider to be a extra MB tax for the high price.
Telling a customer that a car is better engineered when the car is a little like telling someone with a broken refrigerator that is hot inside they bought the best refrigerator on the market. It really doesn't matter that the manufacture thinks or service people about the car, it only matters if the customer thinks / believes their car is a quality car that translates in to a purchase of a new vehicle.
In this discussion and based on this thread and my MB, MB is in real trouble and it will show the near future if these problems are leaving customers with broken cars for frequent failures.
I wish each of you and the people trying to solve your problems the best in solving your issues, as it is not your fault they failed..
Ya'll have a nice day, and remember
THE CUSTOMER IS THE ONLY PERSON THAT CAN DEFINE QUALITY.
The perception of quality and the definition of quality can only be determined by the customer.
Mercedes can not define quality.
Mercedes can listen to the customer define qualilty in engineering terms based on the how well MB listens to the customer, and produces a product that will consistantly deliver what the customer wants.
Example
- The customer wants the battery to stay charged
- The customer does not want to spend excessive time in the dealer for repairs.
And the list goes on.
I have a E500 2003 that I bought new. For the $70G's I thought I was getting a "quality" car. For me quality means only wear / tear items. (oil filters plugs belts etc). Warranty repairs should be almost non-existant.
However in 80,000 miles I have had ignition key failure, door locks, ball joints, total SBC brake failure, air springs and the list goes on.
Granted the car still drives like a new car because I repair with only MB parts each item. But the time in the dealer for service is excessive and cost is what I would consider to be a extra MB tax for the high price.
Telling a customer that a car is better engineered when the car is a little like telling someone with a broken refrigerator that is hot inside they bought the best refrigerator on the market. It really doesn't matter that the manufacture thinks or service people about the car, it only matters if the customer thinks / believes their car is a quality car that translates in to a purchase of a new vehicle.
In this discussion and based on this thread and my MB, MB is in real trouble and it will show the near future if these problems are leaving customers with broken cars for frequent failures.
I wish each of you and the people trying to solve your problems the best in solving your issues, as it is not your fault they failed..
Ya'll have a nice day, and remember
THE CUSTOMER IS THE ONLY PERSON THAT CAN DEFINE QUALITY.
Well said.
The average for a 1/2 wave charger might be only 15 volts if you read it with a voltmeter, but remember it would only be 30 cycles of 30 volts vs 60 cycles of 15 volts. They would read the same.
So without knowing your charger it may have had a peak voltage high enough to damage the system in your car.
However there is one thing you might try.
Disconnect all batteries, the starting battery and (don't think you have this in your C class) the aux battery also.
Let it sit for 24 hrs to totally run down any capacitors that may be storing memory in the system.
Then reconnect and run the new battery install from your owners manual.
This "might" reset your system to function normally.Good luck hope it works for you.
There is another solution, find the 12v+ (terminal 30, perminant power) and disconnect this, replace it with the switched 12v+ (terminal 15). This way the control unit works perfectly when the key is in the ignition, but when the key is out then the seats won't work. minor inconvinece but cheap option.
I'm thinking that I may have only stopped a symptom of the battery drain problem by unplugging the power seat controllers and have not actually found the cause yet. It seems improbable to me that both the drivers side and passenger side controllers would fail at the same time. If one or the other had failed, I could see replacing the controller, but to have both controllers suddenly exhibit the same problem leads me to think that there is a root problem somewhere else on the CANBUS network causing the seat controllers to misbehave.
Lawrence
I have the dreaded canbus sleep mode problem, 1.3 amps constant drain, which I didn't even notice until I let it sit for a couple days waiting for a new water pump I ordered. The car decided someone was trying to steal it at 5:00 in the morning when the battery voltage got low. I'm sure the neighbors appreciated that.
I then found this thread, and disconnected the seat modules one at a time with no change in the current draw, and disconnected all kinds of stuff, no change.
But then I went back and reread Hackman's "woohoo" post, and this morning I unplugged both seat modules, and the SOB (POS) went to sleep!
All anecdotal rambling aside, I was also posting to see if anyone has a clue as to what's keeping the seat modules awake. You have saved me a hell of a lot of time digging around in the wiring harnesses, and I will probably have to go through and unplug the canbus connectors one at a time anyway, but I figured I could thank everybody and mine for more info at the same time...
Thanks again!
Last edited by Scienceguy; Jan 5, 2012 at 03:15 PM.
Last edited by Scienceguy; Jan 5, 2012 at 03:36 PM.
There is another solution, find the 12v+ (terminal 30, perminant power) and disconnect this, replace it with the switched 12v+ (terminal 15). This way the control unit works perfectly when the key is in the ignition, but when the key is out then the seats won't work. minor inconvinece but cheap option.







