Ambient temp weirdness

5ft24 · Post by **5ft24** » 04 Jul 2019, 19:00

New weirdness... 04 XC90 T6. Ambient temp display shows 22f when I turn the key on. It's 70 outside... The temp slowly climbs over about 15-20 minutes almost to ambient.
Any ideas?

Post by **ggleavitt** » 10 Jul 2019, 21:41

Mirror original to the car? Been whacked or repaired recently? Door wiring sound ?

There's a thermistor in the side mirror(s), PN 8650033 for left side of car, 8650034 for right side of car. I've never replaced one but seems as though it can be done. Looks like DDM/PDM (side door switch set is also a module) gets temp as a function of resistance from the mirror sensor then it's low speed CAN (data) to other modules.

What I can't figure out is whether there are two or one. Looks on a wiring guide as if it's just passenger side but then I see a statement in a post from 2015 that notes:

....the driver's side is for the ECM and the passenger side temp sensor is for the CCM and temp reading on your DIM.

Anyone know for sure?

At any rate, it's possible that the temperature sensor is not working properly. I had one of these a couple years ago, replacement passenger side mirror from Erie. Read waay off in the negative direction as well, fixed by replacing the mirror outright since it was warrantied.

** Thanks very much to jimmy57 for confirming. I did check more closely in the wiring diagram and now see 7/105 for the driver side feeding ECM and 7/11 on the passenger side feeding CCM and DIM.

edit 071019- add **

Post by **jimmy57** » 10 Jul 2019, 22:13

on that xc90 there are two like the item you found states. The one on RH mirror is the one making the cluster temp go whacko usually. In some cases it is the DIM (instrument cluster module)

5ft24 · Post by **5ft24** » 11 Jul 2019, 08:18

Ordered both, just going to replace them

5ft24 · Post by **5ft24** » 12 Jul 2019, 06:29

Sensors will be here today. Do the mirror covers just pop off? Can't find any procedures anywhere to open the mirrors, and don't want to break anything.
Thanks

Post by **ggleavitt** » 12 Jul 2019, 09:34

My guess is the mirror assembly needs to come off to do this right- , then you should be able to gently pop the temp sensor plate out (refer to the tabs on the new part for guidance).

Photos show the new part with crimped connector pins, if you don't have a pin extraction tool, you may be able to get the conductors out with a super small flat screwdriver (also see the replacement for the crimped connector tab locations to pry against). Otherwise a good splice (preferably soldered) should suffice.

If you're planning on doing much work on this car see about getting a copy of VIDA loaded up on a PC, links for a 2014D image are around.

Good luck with your repair.

5ft24 · Post by **5ft24** » 12 Jul 2019, 10:35

ggleavitt wrote: ↑12 Jul 2019, 09:34 My guess is the mirror assembly needs to come off to do this right- , then you should be able to gently pop the temp sensor plate out (refer to the tabs on the new part for guidance).

Photos show the new part with crimped connector pins, if you don't have a pin extraction tool, you may be able to get the conductors out with a super small flat screwdriver (also see the replacement for the crimped connector tab locations to pry against). Otherwise a good splice (preferably soldered) should suffice.

If you're planning on doing much work on this car see about getting a copy of VIDA loaded up on a PC, links for a 2014D image are around.

Good luck with your repair.

I've got the VIDA and DICE, 2014D version of VIDA.
It's just at home and I won't be back there to get my laptop until Monday.
I do need to get the EWD to install with it. My copy didn't have EWD

Post by **ggleavitt** » 12 Jul 2019, 14:19

EWD you have to pay extra for, see below for a couple screenshots relating to your specific area of interest.

Ambient Temp Sensor Gen1 XC90.pdf: (366.3 KiB) Downloaded 405 times

5ft24 · Post by **5ft24** » 12 Jul 2019, 14:26

Thank you!