Ledbelly

Hello all,
My 2003 W209 C320 has the infamous clicking stepper motor problem.
Everything works on the passenger side but on the drivers side all the vents seem to work but there is no heat. From this can anybody advise which motor is likely to be at fault and is it an easy one or a pig?
I don't have a charcoal filter and the reset didn't work if that's any help.
Thanks in advance.

Rudeney

You'll need a scan tool that can pull codes from the ACC system. A generic OBDII scanner won't do this - you need one that reads MBZ's proprietary systems. Of course SDS (MBZ's Star Diagnosis) is next, but others that will work are the Autel MD802 Elite, and the iCarsoft i980 or MBII. Once you have the fault code, we can help with which servo or damper is bad and how difficult the repair will be. A few of them are not terrible, require removal of a few pieces of paneling or the center console. There's one or two that require pulling the entire dash, and removing the duct, which also means removing the heater core and AC evaporator, which is a MAJOR job.

Ledbelly

Thanks for that, I'll pull the codes with my iCarsoft and get back to you.

Ledbelly

Ran the iCarsoft this morning, I got three fault codes:

B1598 Component M2/16 (left and right defroster flaps actuator) stiff or blocked.
B15A8 Component M2/15 (left and right footwell flaps actuator) stiff or blocked.
B1100 Normalization of positioning motors is not ok. One or more positioning motors are faulty or normalization has not been carried out.

Bear in mind I'm in UK so it's a right hand drive car if that makes any difference.

Rudeney

It's usually the servos that go bad and you can buy new ones for around US$25. (sorry, can't help with UK prices or sources). They are all the same part for all the flaps/dampers.

M2/16:

http://benzbits.com/w209/Ventilation...frostFlaps.pdf

M2/15

http://benzbits.com/w209/Ventilation...twellMotor.pdf

Those look fairly easy, but the step "remove instrument panel" adds some complexity. You basically have to remove the center console, center stack, glove box, cluster, and other paneling (though not the dash itself). At least you don't have to remove the duct housing, heater core, or evaporator.

Ledbelly

Thanks very much for that, when I find he time to get this done, I'll let you know how I get on.