Member Since: 01 Oct 2015
Location: Edinburgh
Posts: 911
HVAC and heated seats faults - coincidence?
Discovered last night on a drive down the A9 that the front heated seats do not work. Also - at the same time the passenger side face vents do not blow hot air. When on max cool, the passenger side vents blow super cool but the drivers side blow slightly warm or ambient air? No air can be detected at the windscreen or passengers and drivers feet under any circumstances. All fuses and relays under the bonnet related to AC and heated seats appear fine.
All reset or learning options for HVAC with IID tool that I can see have been tried with no change.
Q1. Is the failure of heated seats and AC coincidental? Hoping I can reset things without dismantling the dash to fiddle with flaps and motors.
Q3. Way to fix the cool on one side only/no air at windscreen issue without dismantling the car?
Q2. Is there a single point of failure that would affect passenger and drivers heated seats?
Faults read are these;
HVAC-Ventilation
B1030-87 - Front left seat heater - Bus signal/message failure - missing a message (68)
( on 08-05-2024 19:17:51 at 149200 mi )
B1032-87 - Front right seat heater - Bus signal/message failure - missing a message (68)
( on 08-05-2024 19:17:51 at 149200 mi )
B1081-00 - Left temperature damper motor (2B)
( on 08-05-2024 19:40:58 at 0 mi )
B1082-00 - Right temperature damper motor (2B)
B1085-00 - Defrost damper motor (2B)
B1086-00 - Air distribution damper motor (2B)
B1087-88 - LIN bus A - Bus signal/message failure - bus is off (68)
( on 08-05-2024 20:36:16 at 149201 mi )
B13C2-86 - Windshield misting sensor - Bus signal/message failure - signal is invalid (68)
B13C2-87 - Windshield misting sensor - Bus signal/message failure - missing a message (68)
( on 08-05-2024 19:18:47 at 149201 mi )
B13C2-96 - Windshield misting sensor - Component failure - internal failure (68)
Member Since: 06 Mar 2017
Location: Lost
Posts: 5040
Dave it's ATCM controlled with power inputs from the CJB and BJB. Start with fuses 24 and 27 in the BJB
Then the interior fuse (upper) 15, and in the CJB check fuse 62. You might want to also check for any dampness in there if you have a sunroof. The other thing that springs to mind is the battery voltage must not exceed 16v from the alternator. So that's worth sticking a DMM on there to see if it's below 16v. yµ (idµ - eAµ) ψ=mψ
12th May 2024 4:43 pm
Davethegeo
Member Since: 01 Oct 2015
Location: Edinburgh
Posts: 911
Thanks Prof.
Sadly, all those fuses were OK. All removed and metered for continuity then put back. Took a little longer than expected due to someone dropping Fuse62 down inside the CJB compartment and then also dropping the spare fuse and fuse tool into the same place. Lots of annoying trim removal to retrieve said fuses.
No change. Passenger side still gets cold, drivers side does not. Can't feel air on windscreen or feet.D1 300Tdi - gone
D2 Td5 ES (Alive remapped...mmm) - sadly gone
D4 2012 SDV6 XS - Stolen
D4 2014 SDV6 HSE - Shiny
12th May 2024 8:21 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5040
Member Since: 01 Oct 2015
Location: Edinburgh
Posts: 911
14.6V engine running. No dampness in CJB or the surrounds.D1 300Tdi - gone
D2 Td5 ES (Alive remapped...mmm) - sadly gone
D4 2012 SDV6 XS - Stolen
D4 2014 SDV6 HSE - Shiny
12th May 2024 8:40 pm
Davethegeo
Member Since: 01 Oct 2015
Location: Edinburgh
Posts: 911
How about a vehicle reset using the IID tool or hard reset shorting the disconnected battery leads? Unlikely to do any damage but maybe no point.D1 300Tdi - gone
D2 Td5 ES (Alive remapped...mmm) - sadly gone
D4 2012 SDV6 XS - Stolen
D4 2014 SDV6 HSE - Shiny
13th May 2024 10:53 am
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5040
I was going to suggest that Dave but I am on the road from early. Go for it yµ (idµ - eAµ) ψ=mψ
13th May 2024 2:28 pm
Davethegeo
Member Since: 01 Oct 2015
Location: Edinburgh
Posts: 911
I went for it.
Vehicle reset via IID tool. No change.
Hard reset via spanners and screwdrivers. No change.
Hmmm.D1 300Tdi - gone
D2 Td5 ES (Alive remapped...mmm) - sadly gone
D4 2012 SDV6 XS - Stolen
D4 2014 SDV6 HSE - Shiny
13th May 2024 8:28 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5040
Just home now Dave, I'll have closer look for you tomorrow. yµ (idµ - eAµ) ψ=mψ
13th May 2024 9:30 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5040
Just had a slightly closer look at your codes again and I think B1087-88 may be at the root of your issue.
Possibly an alternator fault or a broken wire!
Talk to you when you get back. yµ (idµ - eAµ) ψ=mψ
13th May 2024 11:21 pm
Davethegeo
Member Since: 01 Oct 2015
Location: Edinburgh
Posts: 911
Interesting! I've had a look at the electrical diagrams and there seems to be many candidates for a broken wire. No idea where to start or where to physically look.
Another slightly weird thing has happened but I'm not sure if it was at the same time as the ATCM prob; the drivers seat used to move when the engine was off and I opened the door to get out. Now the seat just moves a tiny bit. Still moves fine with the buttons on the side of the seat though when needed. All part of the same issue?? Hmm.D1 300Tdi - gone
D2 Td5 ES (Alive remapped...mmm) - sadly gone
D4 2012 SDV6 XS - Stolen
D4 2014 SDV6 HSE - Shiny
16th May 2024 6:47 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5040
Dave I'm not able to access my D4 wiring diagrams for your MY. However, I do have access to the earlier version which shows a LIN bus at the control module C3471-11 (RY). And another from the rear climate module C0695-2 (R).
There is also one from the BMS at C3180R-1 to C0581R-3 (UN) at the CJB, and one from the alternator at C0053M-1 (UN) to the PCM at C0658R-30.
It's possible one of these that's failed but given what you have said I'd be suspicious of the alternator plug and night be worth a look.
Sorry I can't offer anything further but without the later diagram I'd possibly be sending you after "red herrings" yµ (idµ - eAµ) ψ=mψ
16th May 2024 9:19 pm
Davethegeo
Member Since: 01 Oct 2015
Location: Edinburgh
Posts: 911
Slow progress here due to life not being Disco friendly...
I concur with your thoughts about a likely candidate being the LIN bus connection of the alternator.
There is another post https://www.disco4.com/forum/topic173740.h...p;start=15which mentions that when this connection is restored, then the heated screen and seats start working again! Ah ha! But....that problem also involved a charging error which I don't have. Maybe some differences in how the system identifies charging errors between different MY (One wire vs three wires to the alternator..)
Anyway - I'm slowly getting round to getting my hand to that connector on the alternator but it seems to involve finding my coveralls and actually doing it... Still a little unsure where C0658R-30 at the PCM physically is despite my reading of the Italian electrical manual I have. I'd like to meter between this and the alternator when I find it.[/url]D1 300Tdi - gone
D2 Td5 ES (Alive remapped...mmm) - sadly gone
D4 2012 SDV6 XS - Stolen
D4 2014 SDV6 HSE - Shiny
19th May 2024 4:21 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5040
The MY 2011 diagram indicates a connector (C3069M-4 / C3070R-4) roughly mid way between the alternator plug and C0658R-30 at the PCM. (Blue with brown trace)
Is this earlier manual 2011 much different than what you have? I can post it here if you want to compare but I can't access my later D4 diagrams.yµ (idµ - eAµ) ψ=mψ
19th May 2024 4:54 pm
Davethegeo
Member Since: 01 Oct 2015
Location: Edinburgh
Posts: 911
Cheers Prof.
That seems to tie in with a combination of the diagrams I have; MY14 and MY16. Both in Italian so your 3070R is my 3070L. But they show a single wire from the LINbus on the Alternatore going all the way to C2531 via the connectors you have mentioned. Plenty to check if I get a break from work tomorrow.D1 300Tdi - gone
D2 Td5 ES (Alive remapped...mmm) - sadly gone
D4 2012 SDV6 XS - Stolen
D4 2014 SDV6 HSE - Shiny
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