Front left malfunction - Consult workshop - E350

[aero93]

Getting an SRS warning "Front left malfunction - Consult workshop " on E350 coupe.. Anyone else had this? Any idea of the cause? Cost?

[SwissJonese]

My 2008 C350 is booked into the garage in 2 weeks time due to a safety recall to replace the SRS Control unit (airbag control unit). Maybe yours comes under the same recall?

[donkmeister]

First check, and cheapest check, is to test the battery and that it is charging properly.

W211's are particularly sensitive to battery voltage, when it gets a touch low it can cause basically any subsystem to occasionally glitch, without needing to get so low that you would notice sluggish starting or other usual signs of battery failure.

You can do a voltage test through the menu system (user manual explains how), so you can test with the engine on (to check your alternator - should be somewhere between 13.5 & 14.5V) and with engine off (to check your battery, should be at least 12V but 12.5V+ is better). Do the engine off one after the car has been sat overnight, so the battery has run down a little.

The main battery is under the boot floor, and if you have SBC brakes there is an auxiliary one under the bonnet (passenger side near the back on the E500, it might be in the same place on the E350).

[aero93]

Thanks, I should have said its a 2010 C207 - Does the above still apply?

[donkmeister]

aero93 said:

Thanks, I should have said its a 2010 C207 - Does the above still apply?

'fraid my experience only extends to the W211... hopefully Mercedes upped the robustness of the electrics by 2010, but checking the battery voltage and charging voltage is still a good starting point to rule out before spending any money on it.

Also, a Merc indie will charge you around £50 to stick the car on STAR and do a full diagnostic; if it is a dodgy module somewhere this should track it down. I realise that doesn't really help as the car is already saying to "consult workshop", but when I had my first (and so far only) STAR diagnostic done I thought it would be more expensive.