Climate Control Nightmares Topic is solved

V50M66 · Post by **V50M66** » 21 May 2023, 11:26

Hi all,
New here, but been on Swedespeed for a while and messing with old Volvos for even longer.

I have an Emerald Green '98 V70 AWD that I love but has been a constant PITA.

Recently I've been dealing with climate control issues that I cannot for the life of me figure out. The following is a summary of my diagnosis efforts over the past few months.

A few weeks after getting the car initially, I noticed that the driver's side climate control (ECC) was stuck on full cold. Going into the winter at the time, this wasn't going to work, so I replaced the driver's blend door with a known good unit out of my '99 XC parts car. Still nothing.

I then attempted a relearn, which wouldn't complete, so now I didn't have control of the passenger side either (constant light blinking on the module due to being stuck waiting for completion), and it spat out code ECC-211, driver's damper motor position Signal High.

I then tried replacing the ECC module from a wrecked '98 S70. Since it wasn't stuck in relearn, it worked, but only on the passenger side. Now, the driver's temp motor would choose by itself whether to go full hot or full cold - I had no control over this.

I then tried replacing the entire ECC subharness (the wiring harness connecting all the blend door motors to the ECC) and relearning. Still nothing, still stuck in relearn, still with code ECC-211.

I tried replacing the interior temp sensor, no luck.

I then replaced the blend door motor again, this time with the passenger side motor out of my parts car. Still didn't pass, this time with an ECC-212 code.

So I pulled the first replacement blend door apart as described in a thread I saw and cleaned all of the white lithium grease off the contacts and carbon traces inside the unit. Reintalled it, tried to relearn again, and still nothing, with an ECC-211 code.

So I don't know what to do now. I've tired relearning with the ECC module set to different settings, tried driving it afterwards for 3 mins at +20 mph, and followed everything in the 850 OBD app's long list of instructions when performing the self-relearn.

What should I do now? I'm at a loss, and going into the summer, the car is undrivable with the heat stuck on full blast as it likes to do. Thanks in advance for your help.

Oly850 · Post by **Oly850** » 21 May 2023, 11:37

First of all, welcome to MVS, this is the best place to figure out what’s going on with your Volvo. I had a ‘96 850 and worked on it for several years including swapping the dash. I have not seen this issue, it seems like the polarity is backwards in one or more of the blending doors. Are the connectors symmetrical / reversible? Will the system behaves if you disconnect the blending door motor(s) on the drivers side?

V50M66 · Post by **V50M66** » 21 May 2023, 11:52

I believe the connectors are symmetrical. I've never thought about that. I'll try reversing the connector and see what happens. Thanks

V50M66 · Post by **V50M66** » 21 May 2023, 12:26

Nope, connectors are not reversible - they look like they could be, but have tabs to prevent it. So they're all plugged in properly

Post by **FireFox31** » 21 May 2023, 17:08

Could VIDA provide any info even though it's a 1998? Surely the ECC is the same as the 1999-2000 which VIDA works on. I have VIDA in south east NH in case that helps. Anything for a fellow green V70.

V50M66 · Post by **V50M66** » 21 May 2023, 18:56

Nope, it's wildly different unfortunately. Every year P80 is basically a one off it feels. 99+ ECC units won't work - they're wired completely differently. I tried the ECC unit out of my '99 parts car and the whole car freaked out - dash and everything kept turning itself on and off without me touching the key, and then it wouldn't start afterwards until I cleared the codes. VIDA doesn't have any control - everything is done through the 850 OBD app (modern VADIS clone in app form) as if it's an 850, because electrically it's more similar to 850 than it is to 99+ P80. Thanks for the offer - I love this car and really want to get it perfect, just wish it wasn't so temperamental.

xanthefin · Post by **xanthefin** » 22 May 2023, 13:00

I have something.

Live side check Alternator D+ Signal comes through.
If this signal is missing adjustment is not permitted start.

If you have that damper motor reachable and possible turn it by hand.. (?if it lets you gently)

On App Live side look the Step motor damper - Driver. Does it change value if you rotate it normally?

Try on Graph to see if there is no spikes while turning it slowly back and worth.

xanthefin · Post by **xanthefin** » 24 May 2023, 09:03

Hop. I figured out some length how Volvo handles codes off as far i know with their "upgrade" which included your DTC too for "they might not be real faults -- (ECC notices some extra signal)".

Hit email if interested try if you dare test out on ECC which locked on 211 fault code with special commands (though you admit that damper motor behaves badly with sudden changes -- i suspect this could be damper motor or calibration went off in ECC or ECC internal electrical circuit faults which i have seen on one S40...) I will include in next update in über special advanced commands section these then.

V50M66 · Post by **V50M66** » 24 May 2023, 16:43

I'll have to check to make sure it's seeing alternator voltage. Which pins should I probe to find this? I'm almost positive it is seeing it, because if I try to run the relearn without the car running nothing happens (forgot that step once) but with the car running it always flashes the AC and both recirculate lights while it runs. It goes back to just flashing AC on light when it fails after about 10 seconds.

It does let me turn the flap in the case with a screwdriver when the motor is removed - it turns very easily so it's not like it's too much force to overcome or something like that.

I'll have to live graph the position data - wasn't aware I was able to do that. Thanks. I just pull the motor out (leave plugged in) and spin the square metal part by hand and watch the live data?

I don't think it's an ECC module internal fault since it does the same thing across two different ECC modules, and it occasionally throws an ECC-212 code instead.

V50M66 · Post by **V50M66** » 24 May 2023, 17:38

Ok, took a quick look at the live data. It is showing that is sees alternator D+, though all blend door motors are stuck at 0% and pushing buttons for AC and recirc doesn't show on the app either. Not sure if this means anything though, since it's currently stuck in relearn. Will pull the motor soon and cycle it manually, looking at live data as you said.