battery drain, does this effect our cars?
12-19-2012, 06:50 AM
#1
MBWorld Fanatic!
Thread Starter
battery drain, does this effect our cars?
I had a similar problem in my 2002 C240. You can read the thread here.
https://mbworld.org/forums/mercedes-tech-talk/91258-2001-c240-w203-canbus-draining-battery.html
In my case, unplugging the power seat controllers from both of the front passenger seats stopped the battery drain but at the cost of losing both power seats, the SRS system, and the adjustable steering wheel.
I hope your car is still under warranty so you can get it fixed at the dealer. My car is out of warranty so no free fix for me. Personally, I like to work on my own cars but find the W203 extremely frustrating because in my experience so far it seems that all the electronics are tied into the CANBUS network which cannot be diagnosed without the magic dealer laptop.
About your SRS light, were you perhaps playing with the fuses in the fuse box? When I was diagnosing my battery drain, I pulled each fuse out of the fuse box to look for the circuit that was draining the battery. Didn't find the circuit but did discover the hard way that pulling the fuse which provides power to the SRS system and turning the car on will cause the SRS lamp to stay lit until the dealer clears it with their magic laptop.
Just to add a little rant to the end of my post. What was Mercedes thinking by not adding some extra diagnostics to the car so the end user could fix minor problems themselves? Would it have killed them to just have the little malfunction display show the error code along with the malfunction message? It kills me that the computer in the car knows exactly what is wrong with the car but won't tell me not because it can't, but because Mercedes wants me to take the car to the dealer for every little problem. The trade-in value for the car is awful already and I think it's only going to get worse as more and more of the cars come off of warranty with problems which people feel are too expensive to get fixed.
Lawrence
https://mbworld.org/forums/mercedes-tech-talk/91258-2001-c240-w203-canbus-draining-battery.html
In my case, unplugging the power seat controllers from both of the front passenger seats stopped the battery drain but at the cost of losing both power seats, the SRS system, and the adjustable steering wheel.
I hope your car is still under warranty so you can get it fixed at the dealer. My car is out of warranty so no free fix for me. Personally, I like to work on my own cars but find the W203 extremely frustrating because in my experience so far it seems that all the electronics are tied into the CANBUS network which cannot be diagnosed without the magic dealer laptop.
About your SRS light, were you perhaps playing with the fuses in the fuse box? When I was diagnosing my battery drain, I pulled each fuse out of the fuse box to look for the circuit that was draining the battery. Didn't find the circuit but did discover the hard way that pulling the fuse which provides power to the SRS system and turning the car on will cause the SRS lamp to stay lit until the dealer clears it with their magic laptop.
Just to add a little rant to the end of my post. What was Mercedes thinking by not adding some extra diagnostics to the car so the end user could fix minor problems themselves? Would it have killed them to just have the little malfunction display show the error code along with the malfunction message? It kills me that the computer in the car knows exactly what is wrong with the car but won't tell me not because it can't, but because Mercedes wants me to take the car to the dealer for every little problem. The trade-in value for the car is awful already and I think it's only going to get worse as more and more of the cars come off of warranty with problems which people feel are too expensive to get fixed.
Lawrence
12-19-2012, 06:54 AM
#2
MBWorld Fanatic!
Thread Starter
this is the fix for their cars, will it work on ours?
There is a quick, easy, and free fix for this situation.
Basically, it works like this:
There is a plug going into the seat module with three wires...one brown, one red with a colored stripe (often green) and one black with a colored stripe (often white). The brown wire is the ground. The red stripped wire is the constant hot, and the black stripped wire is an accessory hot.
The red, constant hot is used to return the seat to the back and down position and move the steering wheel up and back (convenience entry function) when you remove the key and open the door.
If you don't mind getting rid of the convenience entry function the fix is quite simple. All you have to do is cut the red wire approximately three inches or so from the plug. Tape the end of the wire that runs up into the wiring harness off. Then, take the remaining red wire that runs into the plug and splice it into the black wire. Tape everything up and violia!
Basically, what you'll wind up with after this fix is a seat module that functions perfectly well. The only thing you are doing is converting the module to use two accessory hots as power, rather than one constant and one accessory hot. Again, the only functionality you will loose by giving up the constant hot is the convenience entry. This is because the seat will not move without the key in the ON position (which is when the accessory hots will become live).
Additionally all memory settings will be maintained as they are stored in the module without the requirement of a constant hot.
Let me note that I didn't think of this solution myself, I got it off another forum. But, I thought I'd let you all know that a solution does exist.
There is a quick, easy, and free fix for this situation.
Basically, it works like this:
There is a plug going into the seat module with three wires...one brown, one red with a colored stripe (often green) and one black with a colored stripe (often white). The brown wire is the ground. The red stripped wire is the constant hot, and the black stripped wire is an accessory hot.
The red, constant hot is used to return the seat to the back and down position and move the steering wheel up and back (convenience entry function) when you remove the key and open the door.
If you don't mind getting rid of the convenience entry function the fix is quite simple. All you have to do is cut the red wire approximately three inches or so from the plug. Tape the end of the wire that runs up into the wiring harness off. Then, take the remaining red wire that runs into the plug and splice it into the black wire. Tape everything up and violia!
Basically, what you'll wind up with after this fix is a seat module that functions perfectly well. The only thing you are doing is converting the module to use two accessory hots as power, rather than one constant and one accessory hot. Again, the only functionality you will loose by giving up the constant hot is the convenience entry. This is because the seat will not move without the key in the ON position (which is when the accessory hots will become live).
Additionally all memory settings will be maintained as they are stored in the module without the requirement of a constant hot.
Let me note that I didn't think of this solution myself, I got it off another forum. But, I thought I'd let you all know that a solution does exist.
12-19-2012, 08:17 AM
#3
I had a similar problem in my 2002 C240. You can read the thread here.
https://mbworld.org/forums/showthread.php?t=91258
In my case, unplugging the power seat controllers from both of the front passenger seats stopped the battery drain but at the cost of losing both power seats, the SRS system, and the adjustable steering wheel.
I hope your car is still under warranty so you can get it fixed at the dealer. My car is out of warranty so no free fix for me. Personally, I like to work on my own cars but find the W203 extremely frustrating because in my experience so far it seems that all the electronics are tied into the CANBUS network which cannot be diagnosed without the magic dealer laptop.
Lawrence
https://mbworld.org/forums/showthread.php?t=91258
In my case, unplugging the power seat controllers from both of the front passenger seats stopped the battery drain but at the cost of losing both power seats, the SRS system, and the adjustable steering wheel.
I hope your car is still under warranty so you can get it fixed at the dealer. My car is out of warranty so no free fix for me. Personally, I like to work on my own cars but find the W203 extremely frustrating because in my experience so far it seems that all the electronics are tied into the CANBUS network which cannot be diagnosed without the magic dealer laptop.
Lawrence
i cant possibly imagine approaching an mb troubleshoot without das.
spent the $350-400 or so and you are a go. the first time you use it it will pay off.
12-19-2012, 01:23 PM
#4
Super Moderator
Mercedes is at work to shut down all non authorized diagnosis units by requiring more online coding in the newer cars such as the 204 and newer series.
it's only a matter of time
it's only a matter of time
12-19-2012, 06:47 PM
#5
MBWorld Fanatic!
Thread Starter
my actual question is, do our cl class suffer from this problem with the power seat controllers, or are they limited to the c240's?
12-22-2012, 06:04 PM
#6
MBWorld Fanatic!
Thread Starter
bump
