[Jarek]

I have my car scheduled for detailed diagnosis next week so I will update after that.
In the meantime have spotted that driver seat memory is also not working - not reacting to memory buttons.

[Jarek]

Detailed diagnosis returned... nothing! Everything seem perfectly in order (aside from not working, typical SNAFU).
However it revealed that there are no options for heating/venting buttons in HVAC module - like the car was not equipped with heated/vented seats (which is not the case as we checked factory trim). HVAC firmware was updated to latest version but no improvement. Now the question is which module controls HVAC as this may solve the problem.
And since there was an issue with accessing schematics yesterday we had to postpone diagnosis until my mechanics gains more info on the topic.

[ember1205]

Sounds like a part was replaced during the rebuild that was not the correct one? I'd start checking the various BCM's toward the rear portion of the car since you had mentioned the rear end had been damaged / rebuilt.

[Jarek]

Thank you for suggestion ember1205 however this may be sth before the crash as I was overseeing the rebuild and approving purchase of all parts - no electronics was replaced, and around the seats there was only the seats tensioners fix. On the other hand they mechanics were checking/deleting errors with diag tool - maybe they re-programmed some module by mistake.
Right now we will go by schematic trying to check what was programmed wrong.

[cam765]

Here are the wiring diagrams for the heated and cooled seats.

[supratau]

had same problem, fixed with body computer via SPS programming

[Jarek]

Hi Everybody,
Seems that there is 2 of us sharing the same issue (@raidaru) - seats not heating/venting and no reaction from HVAC (after buttons are pressed no LED lights show).

So far I was able to track the signal from HVAC to the SHC module under passenger seat (so far the monitoring allowed).
Raidaru swapped SHC module and whole HVAC panel (from the car that works) but also was unable to fix the problem.
As there is nothing else between the SHC module and the blowers/heaters maybe BCM needs to be checked - re-flash was suggested before.

Just another hint: In my case also driver's seat memory is not functioning - not sure but it may be connected.

@cam765 what are the J38* items on diagram (are those connectors that should be checked)?

BR,
Jarek

[SATINSTEEL1LE]

Fuse.

[Jarek]

Originally Posted by SATINSTEEL1LE

Fuse.

Fuses were checked as the 1st initial step - not it.

[Jarek]

We have one one more colleague with this problem (@ejik418).
He also did some investigation: re-flashed BCM - with no result, then replaced seat module under passenger seat - with no result, then replaced BCM and reprogrammed it - with no result, then replaced memory module under the driver seat - with no result, as well.
Looks like all 3 modules are not the culprits here.

[cam765]

The J*** are locations where wires come together (junctions) and can be identified on schematics like the one below. I don't really understand how these would help you. You would be better of using actual connectors as places to probe around in (like X310 or X320, anything that starts with an "X").

[Jarek]

Thank you cam765.
I was just checking if J*** are not connectors as well. Looking for a place where the signal may get lost after arriving to SHC module. But it seems that after SHC there is nothing more than the fans and heating pads.
SHC would be the suspected for being broken but ejik418 replaced that with no success (along with BCM and Seat Memory module and we are sharing the same set of symptoms here - 1. not working heating/venting, 2. not working seat memory, 3. triple unlocking command from ABS module).

I begin to suspect that maybe the problem lies with ABS module, preventing SHC from handshake with BCM and/or HVAC to start heating/venting.
Another option are pre-tensioners that were replaced in the seats - maybe they have some electronics inside as well - messing with the commands from SHC.

[cam765]

Although not an easy task, viewing CAN log data would be tremendously helpful in cases like this (I believe you mentioned some of this was done previously). Being able to quickly see whether or not pressing buttons on the HVAC controls sends commands correctly and seeing how the SHCM reacts would be helpful.

This is not ideal, but insulation piercing probes could be helpful in this situation where connections are infrequent.

[Jarek]

Originally Posted by cam765

Although not an easy task, viewing CAN log data would be tremendously helpful in cases like this (I believe you mentioned some of this was done previously). Being able to quickly see whether or not pressing buttons on the HVAC controls sends commands correctly and seeing how the SHCM reacts would be helpful.

Thank you cam765 - I need to ask my diagnostic guy if we have some logs stored from the last time or if we need to take new ones.