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W203 220 cdi 2001 battery drain over night - Printable Version

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W203 220 cdi 2001 battery drain over night - shefi - 17-05-2019

Hi all! I have checked almost every thing on w203 and everything works okay.i have clamped an amp meter and it shows 1 amp, its to much. When i remove dashboard fuse 7.5 amp fuse, current after some seconds disappear. So i thought my problem is dashboard but no. I replaced with another known good dash and the same think happened. So my suspect is CAN network. How CAN network drain 1 amp? Can someone help me understand why CAN is not sleeping and after i remove dashboard fuse it goes off?


RE: W203 220 cdi 2001 battery drain over night - Rpinheiro - 17-05-2019

Dear Shefi,

I would take these steps to see what is messing with the battery drain. It will take some of your time and patience.

1) In line ammeter on the battery to measure current accurately (Down to 10ma) - see what it pulls. (Need to wait for 5 or 10 mins so it drops to minimum as things shut off.)
2) Pull all the fuses, 1 at a time to see if it makes a difference to the drain current. Disconnect the alternator if the fuses make no difference.
3) If nothing obvious, make sure any auxillary stuff is disconnected - phone, sat nav, after market radio etc etc. If none of the above, probably a canbus error - Proceed as follows.
4) Find a spot to look for can signal, put an oscilloscope on it, and look for signal.
5) Measure current and signal, see if the 2 are related, monitor over 24 hrs, and see if the canbus, either fails to shut off, or wakes up.
6) In the event of a can error, remove each of the can units, one by one, to see which one it is.

Thanks in advance
Ruben


RE: W203 220 cdi 2001 battery drain over night - gera64 - 18-05-2019

Hello mate
most electrical commands in the driver's seat consume current
try disconnecting the seat command module
(under the seat you will find the module)
then he tells me


RE: W203 220 cdi 2001 battery drain over night - bekhit - 20-05-2019

check outside temperature sensor