S40 Air Con Problem

hayd · Post by **hayd** » 18 Jul 2013, 09:34

I have a 1.8 petrol S40 2007 model which has dual air con and heated seats. There appears to be a fault in the drivers side air con and seat. The passenger's seat and air con work as they should, however on the drivers side, the temp will stay hot even when set to cold and the seat does not work. Took it to a local garage, who stated that it was a fault in the unit under the dashboard which has been replaced.
However, a new fault has now occurred, passenger side still works as it should, but on the drivers seat, the temp is now cold and the heated seat still does not work.. Apparently, a fault has now come up with the code communication sensor error.
The garage is a at loss and has replaced the dashboard etc back with the new motor (has not charged me for the work as he couldn't fix the issue). Does any one have any ideas or is it a trip to a main dealer.

Thank you

Post by **jimmy57** » 18 Jul 2013, 09:48

The seat heater module and the motors that move air distribution and temp control doors on the same side use a communication network to the climate control module. The seat heater module (effectively a relay with communication capability) has an issue with failing and it shuts down the comm network and that stops temp control on that side.
Does the shop have the capability to read full car for codes? The CCM should have a LIN bus (LIN bus is the comm network for climate in this case) error code for LIN bus #2.
If they unplug the seat heater module under the seat with key off and then turn key back on the temp control should work as that stops the communication issue.

hayd · Post by **hayd** » 18 Jul 2013, 11:11

Many thanks for that reply, not very technical minded is the seat heat module easy to locate underneath the seat.

hayd · Post by **hayd** » 18 Jul 2013, 11:13

Many thanks for that reply, not very technical minded is the seat heat module easy to locate underneath the seat.

Post by **jimmy57** » 18 Jul 2013, 11:59

Yes, it is clipped under the seat on the seal frame. Push the seat all the way back and then tilt front up as
high as it goes.

hayd · Post by **hayd** » 21 Jul 2013, 04:39

sorry to be a pain, I have looked under the seat and I can see what appears to be two sets of connectors, one is set towards the front and has thick cable leading to it with numerous pins and connectors leading to it, whilst the other one is set towards the rear and appears to have two plugs in it which are green and grey.
Am I correct in assuming that it would be the rear one that I will need to disconnect.

Thanks

Post by **jimmy57** » 21 Jul 2013, 09:14

You should be able to identify the module as it is 1 inch thick by about 2 by 1 3/4, all approximate dimensions. The module is attached to seat frame with a plastic "rivet", you have to pry the center pin out as that pushes in and expands the rivet thing to hold seat heater module to the frame.
I don't have a car I can look at for better info and it has been at least a couple of years since I changed one. I do believe the one at rear is the correct one. Raise rear of seat and look for the module to be sure. Here are pictures of what you are looking for. The connector on left in the pic with wires on SHM is the one you can unplug to see if the aircon goes back to normal.

hayd · Post by **hayd** » 26 Oct 2013, 09:48

Jimmy, thanks for all your help, have tried all of the above and still no joy, looks like I will have to take it to a main dealer and see what they suggest. Once again, thank you

hayd · Post by **hayd** » 16 Jan 2014, 08:50

Have just tried another dealer and the error message Lin Bus 2 came up. Dealer unsure and sent it back unfixed, any ideas please