No heat after replacing Cabin air temp sensor Topic is solved

Post by **wizechatmgr** » 07 Feb 2017, 13:49

I am now getting 0% on all the damper motor potentiometers from the CCM - 4 if I remember correctly. My feeling is the CCM just crapped. I just installed a new Cabin Air Temp sensor - it is reading fine - which figures. I have reseated all connections to CCM - no luck. All pins are seated within their plugs correctly.

I received and cleared a CCM-236 code - Damper Motor position sensor, recirc signal too low. Code isn't coming back but the AC on button keeps blinking green. I am no longer able to change the air destination selector and have the air follow it. According to dice it is registering the input, but all of the sensors show 0%. I'm guessing a fried A/D converter in the CCM. I've tried sending the command to activate the calibration using DICE - thus far it doesn't appear to make a difference. The blower motor still responds. Is there a way in the interim to get those dampers into the heat position so I don't become an icicle? Could this still be a fuse issue since all of the dampers are doing the same thing at the same time? I doubt it but I wanted to throw that thought out there.

I have no "usable" heat. I tried searching the forum the words CCM and Heat are too common.

1. How does one verify my conclusions? I'm guessing I should probably check the resistances from the potentiometers on the dampers by pinning out the harness going to the CCM. Do we have a cheat sheet laying around as to which pins are what or should I dig deep and find a proper electrical schematic?

2. If I move the damper motor using bypass power - is it likely the CCM is going to try to set it back to cold again just to further poke me in the eye?

Of course this happens during a snowy week. Never on a warm, dry week, where it could fail to cold and I wouldn't have a care in the world.

I have another CCM ordered and on the way, just trying to see if there is something here I can do in the interim. Pulled it apart and I see no visible issues (no burned resistors or diodes - nothing obvious)

Any other ideas?

Post by **oragex** » 07 Feb 2017, 14:03

Was the thermistor the same value as the original one?

Post by **wizechatmgr** » 07 Feb 2017, 18:21

As far as I can tell, yes. It shows a correct cabin temp now in DICE. The passengers compartment temp and motor codes are gone for that sensor.

Post by **wizechatmgr** » 07 Feb 2017, 18:32

Note to self - hold recirculation and off together - appears it may start a calibration cycle if held for ~3 seconds while running.

Post by **oragex** » 07 Feb 2017, 19:22

Which buttons have you kept depressed ?

Post by **scot850** » 08 Feb 2017, 11:20

Did you have any success with this? As oragex mentioned, some clarity on what buttons were pressed would be great please.

Thanks,

Neil.

Post by **wizechatmgr** » 08 Feb 2017, 15:26

No success yet as I'm waiting for the "new" module.

Make sure you're on recirc and the AC is set as off.

Press and hold the the AC Off and Recirculate buttons together. You hold them until they suddenly have the AC on illuminate solid. Release and all 3 blink. I believe this is a calibration cycle. Doesn't help me much as I think I blew up the A -> D Chip(s) since all the potentiometers on my motors show 0%. I have a "new" module that should arrive Friday-ish. Hope to install it and try again. If I'm right I should be all set to go, we'll see.

Post by **abscate** » 08 Feb 2017, 18:38

Im not sure thats right. I think the blinking is just telling you there is a fault.

Isn't there a danger to using DICE On a CANBUS car - I seem to recall Lee having a bad experience with that??

I think I have spare ECC parts from a 1999 parts car in my stash and of course IM local (except down in DC rest of this week)

Post by **scot850** » 08 Feb 2017, 19:52

Dice should be fine abscate as it is a 99 according to OP's profile.

Neil.

Post by **wizechatmgr** » 08 Feb 2017, 20:37

DICE supports such cars. There is great risk if you initiate the wrong commands and attempt a firmware flash with the wrong file, attempt to change a checksum, etc.

I am supposed to have the new CCM/ECC module either tomorrow or Friday, postal system willing. If that doesn't work then I have a harness to pin out and start verifying every component of the system - starting with those servo motors and potentiometers.

You got out of town just in time for the snow abscate :p