Hey guys,

I've come across an annoying issue with my 2004 w203 C270CDI. Our winters here are rather cold <0°C and damp, and my car is getting all weird during the winter season:

• As soon as I start the engine, the steering wheel button back-light is flickering like crazy, the buttons themselves don't really seem to be responsive - it takes like 50 repetitive pushes to go through the menu.
• Both long beams are flickering the same way as the steering wheel button back-light. Low beams are fine.
• The horn isn't really working too.
• Turn signals keep resetting.
• Windscreen wiper 1st speed (the one with the pause) is just not there - its non stop (2nd speed) only.
• ESP is not working.
• Last night the brake fluid light went off.
• Occasionally the SRS light comes up too.

Essentially its all a big mess when the engine is cold. The issues are only there when the engine is cold, it's all fine when it warms up to 80°C.

I am blaming the front SAM module for all of this, but I can't seem to link the cold engine with any of the issues. How can it all go back to normal when the engine warms up? Same thing goes for the rest of the year - when it's not cold outside - there are no issues with the car.
I would appreciate your thoughts on the matter.

Best regards,
M

 

Do a short test and post results here.

 

2.93 A draw. how much is allowed?

 

my bad. the trunk light was on. 0.08A.

 

Short test means a diagnostic readout of all the ecu fault memories.
80 ma is okay, usually it will drop to around 30 ma.

 

Do you mean the one through the radio console, or a proper one with a code reader? First one is empty, 2nd one will take some time to do, as sadly I don't own the reader.
Meanwhile, can you see anything in the crystal ball?

 

Crystal ball says plug in into an sds

 

Just an update on this long forgotten thread, perhaps someone will find it useful.

If you have any similar symptoms, replace the 2 parts in the N80 steering column module (there is no N80 part, its an assembly of units): A0004640618 and A0025428618.

All of the issues are gone now. Seems like the CAN module converting the signals from the steering wheel was malfunctioning when it was cold.

PS also, if you have issues like your key recognition is intermittent - please check if you don't have tiny fluffs of dirt inside the keyfob. That almost cost me a fortune too.