98 V70 ECC Drvr HOT Pass COLD Issue Topic is solved

[sleddriver]

98 V70 T5 Original Owner 210,000mi.

About a week ago, the drivers side air temp went to Max HOT. The drivers temp control had no effect. The pass. side was normal and adjustable. No amber or green flashing ECC lights. Drove to my indy who has a Volvo tester. Pulled the following ECC codes:

ECC_211: Drive Temp Motor Position Sensor
ECC_414: Cabin Temp Fan Motor- Signal Faulty

I then attempted to reset or reinitialize the motor position adjustments using the tester. Communication with the ECC was verified, the green LED on the AC ON button began flashing but the reset failed. I then pulled this code:

ECC_422: Self Adj. Drive Temp Motor - Failed.

I was unable to ERASE any of these codes. We looked through some ALL-DATA sheets on the above codes, but didn't go through ALL the pages. When I left the green AC ON LED was still flashing and remains to do so as long as the IGNITION is on. I've never seen that before. Flashing amber LEDs in the past, but not this.

Reading up on this issue, I pulled the driver temp motor, made an index mark on the shaft & case, opened the case, marked both gears with an index mark, verified the motor still worked with a 9V battery, cleaned the carbon pads, checked for solder/trace cracks and verified continuity between the various five pins. Then regreased a few turning friction points and reassembled.







While working on this, I disconnected the neg. battery cable to reset the ECC and force it to go through the damper adjustments. Upon reconnecting the battery and starting, it failed to do this. I now noticed the drivers air temp was COLD, the pass. side was HOT (even both temp controls were set on COLD), air only came out of the four dash vents and I was now unable to control which vents it came out of! Also, though the RECIRC control was not enabled, the RECIRC door was set to only pull air from the pass. compartment. Thus, it was in RECIRC mode. Wasn't doing this before. The blower fan worked and I could enable the A/C. That's it. None of the large three dials (drvr temp, air direction, pass. temp) did anything. No flashing amber lights either, just the flashing green AC ON Led.

Go figure..........

So something is FUBAR with the ECC. It's TANGO UNIFORM and won't reboot/reset.

Next, I pulled the cabin temp sensor and when disassembling it, pulled the dam head off of the pinhead thermistor! $%^+! I'd carefully cleaned it like this in the past (it is the original part), but really screwed the pooch this time. (That dam thing is expensive too....rats). I stripped off the TM ends and wrapped them around a 10K Ohm resistor for now. Reinstalled it and the tiny fan spun it when the key was on.

So what the hell is going on here?? I can't get back to my indy's until Monday AM. Weather here is in the mid-50's F fortunately. I have no floor nor defrost air capability and an ECC acting very odd after being "tickled" by the tester.

Any ideas?

[dosbricks]

You at least had a good idea about cleaning the cabin temp fan motor even if it didn't go exactly as planned. It would be nice to swap in another ECC even if it is not confirmed working perfect, just to see what happens, since so much has gone haywire.

At this point, a visit to the local pick-n-pull yard might be worth it to harvest an ECC and a cabin temp fan. Where in TX?
C.C. Pull-A-Part has two 98 V70s the last time I was there.

[abscate]

Very cool look inside the damper motor, I had not seen inside one if these before.

[erikv11]

I would try to force the motors to calibrate, you need something like VIDA or a homemade tool, and you need to be careful about how the motor shafts are oriented (e.g. https://www.matthewsvolvosite.com/forums ... =1&t=62415).

[sleddriver]

You at least had a good idea about cleaning the cabin temp fan motor even if it didn't go exactly as planned. It would be nice to swap in another ECC even if it is not confirmed working perfect, just to see what happens, since so much has gone haywire.

At this point, a visit to the local pick-n-pull yard might be worth it to harvest an ECC and a cabin temp fan. Where in TX?
C.C. Pull-A-Part has two 98 V70s the last time I was there.

Re: CTFM. Fate eventually caught up with me! There are 5 clips on that little thing to unseat. I looked up bead-size TM's. Read somewhere that this one is probably NTC, and since it's got to be very low power, the resistance will be high, thus the 10K resistor. I may go to 100K.

Re: Location. NW of Austin. Where's the CC PAP?

[sleddriver]

I would try to force the motors to calibrate, you need something like VIDA or a homemade tool, and you need to be careful about how the motor shafts are oriented (e.g. https://www.matthewsvolvosite.com/forums ... =1&t=62415).

Having VIDA for the sled would be nice. No joy there unfortunately. Is it still available somewhere? Please elaborate on the home-made tool.

I read the link you posted. he said "the air dist. damper failed", thus preventing calibration. Not sure how a damper can fail. Stuck? Plastic end stripped?

It's odd that the HOT & COLD is now reversed. Formerly, driver was HOT; pass COLD. Now it's reversed. Odd that....the drvr temp damper "flops" to COLD when the motor is removed. I stuck a screwdriver in there and easily moved it to the other limit, which I guess is HOT. I also made sure to index the motor, which is seen in the photo, and it's about in the center of travel.

I don't own an OBDII tester/reader of any sort. Does VIDA run on a laptop with a cable connecting it to the car?

[dosbricks]

Re: Location. NW of Austin. Where's the CC PAP?

Corpus Christi. Austin is Volvo capital of TX with UT and an educated populace. You should be able to find plenty of spares there. A used ECC is about $30 if you decide to give it a try.

But Erik is probably steering you onto the right track. When it comes to electronics, I'm more of a parts changer than anything resembling a technician.

Damper plastic ends do strip. There is a thread in the repair section of ways to deal with it. Although I don't have it, pretty sure VIDA runs on a laptop. Erik will elaborate--he is a faithful watcher of this forum. Or someone else knowledgeable will chime in shortly.

[sleddriver]

Austin is Volvo capital of TX with UT and an educated populace. You should be able to find plenty of spares there. A used ECC is about $30 if you decide to give it a try.

I remember when that certainly was the case. I drove a SAAB 900T and there were plenty of those as well. But those days are long gone....Very rare I see V70's or S70's. I see more of the XC90's.

[sleddriver]

Update:

First start of the day. Set ignition to II and pressed RECIRC 3x as fast as I could. No joy. Key off, then on, then again. No joy. Still the blinking AC ON led. So I started the car and went for a short drive. After about a mile, I noticed the amber OFF and RECIRC led's flash several times, then quit. I also noticed the air on both sides was now coming out of the floor vents. That's different. The air was also warm on both sides, but not anywhere near HOT. Temp & air dist. controls had no effect. Yesterday, air only came from the dash vents and the drvr side was COLD while the pass was HOT.

After driving about 5 mi., I shut her down, waited about 30 sec and did the ignition II, press RECIRC 3x within 3sec multiple times. No joy.

I'm really lost here. In 17yrs of owning this car, the climate control has never given me ANY problems. I'm lacking an thorough explaination of how it all works too. I found an online 850 manual, but the damper motors are different and of course, you can't pull codes from a 98 V70 like you can from a 97 850, unfortunately.

[sleddriver]

Found this link on MVV while searching around:
https://www.matthewsvolvosite.com/forums ... 25&start=0