Direction indicators have suddenly malfunctioned, hazards working fine.

[Alex Crow]

I would not bother, very little chance of seeing anything wrong!

In the workshop we would be doing diagnosis with STAR, checking live data in the EIS and front SAM for starters.
It will be hard to diagnose this further without...

 

[brigill]

If this is the last W202 with EIS (electronic ignition switch), the combination switch is wired into the ignition switch, with just the one wire, giving a 'voltage coded' output. If we had a voltage supply or continuity problem somewhere between fuse no.22 in the front fuse box and the EIS that would account for the N/S flashing when the stalk was turned to the right.

To test, check the black wire to pin6 in plug B at the EIS - should be battery voltage turning one way, and probably half that for the other way.

If the values are correct, suspect an EIS fault (we have seen similar with non functional horn being due to an EIS fault).

If voltage is too low, suspect a wiring or power supply fault between the fuse and EIS.

The EIS sends the flasher signal to the front SAM via the CAN bus btw.

Hello Alex,
I have a C320 CDI (2008) W204 which has developed a puzzling problem.
On a long journey,about 1 hour (or approx 50 miles) the indicator stalk stops working. Everything on the stalk stops working. I pull over and switch the ignition off wait a minute then switch back on and everything works normally for the rest of the journey...up to four hours. This happens every time I drive over an hour or so (the last several times anyway). The most unsolvable problem? I can't take it to a MB garage because they'd have to drive it an hour to see the problem and then - what would they suggest?
Hope you can help because it could be quite dangerous one of these days as screen wash, flasher, and wipers are all on this stalk. (fuse 13 is in tact)

 

[television]

What a horrible fault something I cannot recall seeing before. It could be a CAN fault. I wonder if you asked Cole at MBS if you could just pop in when the car is playing up and he could join up to STAR.

 

[brigill]

indicator stalk W204

Hello again television, Thanks your reply - you will see that there's no point in taking the car anywhere if the fault only appears after one hour or 50 miles!! Otherwise everything is fine (I really like the car) - It is interesting though and I could take it in to Southampton as a challenge to Cole!?
I do these long journeys about every 5 or 6 weeks otherwise as long as my journey is less than 50 miles I don't get the problem.
I'm disappointed though because I had an Audi once that developed an electrical fault that occurred regularly but never when I took it into the Audi garage and spent a lot of money but never cured the problem ...and now I'm developing something similar with MB.

Not sure what the SAM is - is it the fuse box under the bonnet on the drivers side? I had the fuse for the indicator stalk out to check and clean but it can't be this. matbe some component on the SAM PCB?
I don't suppose anything would show up on the diagnostics with Cole?
What would you suggest as a first action if your car developed this fault?
I'd be grateful to know
All the best
Brian