Driver heated seat not working....
 

My 2012 V40 has just had it's first wobble.... the drivers heated seat has stopped working.

It was serviced last week and i did wonder of a software upgrade and erased the higher settings i'd programmed in to the CEM but I've checked with VIDA and they're still there.

The dash indicator is working as it should and the passenger side is still working, so my next plan is to remove the seat or get under it with a multimeter to diagnose it.

Anyone know if there is a common fault on these and if the heating pads are available separately? The last heating pad I replaced was on a 1994 440.....

EDIT: Just found this on another forum... so I'll be looking at that.

first of all check the fuses - Fuse 34 and 35 in the underseat fuse box run the heated ftont seats. If the LED and display icon don't come on when you press the button, it means the Climate Control Module knows it can't talk (or is getting no response) to the Seat Heating Module (it controls the seat heating by sending LINbus messages to the SHMs).

If it's not the fuses, it could be a fault in the SHM itself, a broken heater element, or possibly the temperature sensor (the SHM controls the temperature by reading from a sensor embedded in the seat squab). If the sensor has failed or one of the heater elements is faulty the SHM probably rejects any requests from the CCM to turn on the heating (i.e. it fails safe). There are diagnostic test functions in VIDA to check the SHM functions, and faults would show up as error codes from the CCM , but that probably requires a trip to the dealer

Yep.... RH Seat Heating Element - General Electrical Failure....

The CCM will need calibrating , both my heated seats stopped working and i could not find any issues like blown fuse or element broken , so i thought what is common to both seats the CCM , so i did a calibration and bingo both seats get hot

Thanks but the CCM is specifically reporting a general electrical failure via the SHM(R) module. I need to get to the bottom of that first as if that is correct - it's never going to work.

You haven't mentioned the specific code(s) in question so have you worked through all of the possible reasons for the fault code which are listed in Vida?

Not yet but VIDA lists the possible causes as the seat heating circuit being open circuit, short circuit, or shorted to ground.

So I guess I need to unbolt the seat and meter it through to find where the fault it. Hopefully a damaged connection or broken wire but if needs be I'll remove the seat cover and inspect the pads.

I've fixed a few old 440/850 heating pads where the wires had snapped at the connection to the thermostat, so hopefully it's something similar but I've checked with the dealer already and a new pads is apparently circa £40 so not extortionate.

I just need to crack on as I want to sell the car now I've got another XC60 :-) If I can sort this it will be electrically & mechanically 100%.