98 V70 ECC Drvr HOT Pass COLD Issue Topic is solved

[scot850]

I used to visit my local PnP yards on a regular basis last year, and usually if they had a 50% off regular visitor event, I'd pull spare parts.

ECC units were about $20 and the temp sensor were about $3-5 or so. Little effort to remove.

The servo motors were also cheap around $5-10 if I recall. They can be a pain to remove, particularly the mixer motor up on the LH side of center to the left of the speedo console. I tried to keep an eye out for cars that someone had removed the glove box or dash as they usually don't remove the motors. Having said that, I have only ever had one motor that was a problem. The easiest motor to remove is the one for the fresh air vent behind the glove box, it only has one mounting screw.

The link that was attached is useful. If you need diagnostic software for your 98, look in the tools section for vol-fcr software and link cable for OBD hook-up if you have a laptop available. The cables sometime come with the vol-fcr software, and there are older versions for free if you look on-line. I bought a used laptop from our local electronics recycling center for about $200 (Dell with i5 processor) and it had Win 7Pro which I use for my Vida/Dice and vol-fcr.

Neil.

[erikv11]

Apologies, I forgot that the homemade OBD flasher tool (like in the link from jreed) will not work for a 98 ECC. I just checked it to be sure because the info I could find by searching was unclear: I could not get the gizmo to respond at all in my V70, then I walked over to one of my 850s where it flashed upon connection then pulled a couple ECC codes no problem. Definitely a no go in a 98.

I do not really know the ECC intricacies, have only been drawn in to that labyrinth a few times. But I do suspect a key issue here is calibrating the motor(s) properly. jimmy57 or Ozark Lee could probably help if you want to PM them, or maybe others, hang in there.

[sleddriver]

Update II:

Using my indy's Volvo tester, I pulled the following codes:

ECC-414 Cabin temp fan motor - signal faulty. Counter = 18
ECC-211 Drive temp motor position sensor - signal too high. Counter = 77
ECC-422 Self Adjust drive temp motor failed. Counter = 31
Ecc-212 drive temp motor position sensor - signal too low. Counter = 1

Using the tools monitoring function, I was able to verify that the fan slider, mode knob, Ltemp & Rtemp knob, RECIRC, AC switch all work. As I rotated the knobs, the status screen on the Volvo tester updated to reflect the new positions. The cabin temp sensor fan was also detected ON and the solar sensor responded to different levels of light. Therefore, the ECC appears to be functioning.

I erased all of the above codes. However when attempting to adjust the motors, the test failed and a single code was set:

Ecc-212 drive temp motor position sensor - signal too low.

I successfully erased this code, attempted to adjust the motors again, and it failed. The single code set was ECC-212, as above. I did this a few more times, then manipulated all the ECC wiring, connectors, the temp motor connector, and reran the test. It failed, setting the same code: ECC-212.

It appears that NO calibration/adjustments will be performed until ALL codes are clear. Thus any climate system faults will FUBAR the entire ventilation system. I rarely use it on AUTO....now I can't use it at all!

So I'm going to pull it out, retest it, verify the resistance range settings at a couple of points and do some probing on the ECC connector itself. "Signal low" to me means (1) There is no signal, (2) the value is low out-of-range, (3) The signal is dropping out or intermittant, (4) other?

[sleddriver]

Here are some more excellent links on repairing these motors and troubleshooting HOT/COLD issue:
https://www.matthewsvolvosite.com/forums ... hp?t=54750
https://www.matthewsvolvosite.com/forums ... 8&p=254621

Found this schematic as well. You can see the five motors on the right side in a vertical line. Note pin one of all motors are tied together and grounded. Pin 2's are also all tied together to an output of the ECC, either a voltage or current. The position feedback is taken from Pin 3 on each motor as an input to the ECC. So this tells me that the signal from pin 3 is the signal referred to in the ECC-212 error code "...signal too low". Note this diagram may be from a 97 or earlier 850. Note the two cabin temp sensors at the far right, labeled 7/65 and 7/64.

[sleddriver]

I pulled the suspect temp damper motor yesterday and made some test leads for it. This enabled me to test the potentiometer while rotating the motor with a bench supply. I meas. 9K44 Ohms across the pot. Min. resistance meas. 228 Ohms. Max. was 9k3. So midrange is 4k54. I set it there, then reinstalled. I now realize I have to drive it before theh ECC will initiate the calibration sequence. I could hear the motors turning and feel the dash air come on, then off. However, the amber lights then illuminated, indicating no joy. Presently I'm back on dash air with just a touch of floor air. Temp is back to 100% HOT. Not bad since it's in the 50's F here.

An indy friend allowed me to check a new motor. Total resistance meas. 9k94 Ohms. Min. resistance was 278 and Max. was 9k8. So my min. & max. are inside this range. Perhaps this is "too low" as indicated by the error code? If true, that's mighty fussy! Then again, the car sure is fussy regarding P0455. I wasn't able to pull any codes yesterday, so I'll do that today.

At this point, the motor tests OK. And I can measure a resistance similar to what a brand new motor measures. So I don't see a defect in this motor. I'll have to pull some codes to see if something has changed.

[sleddriver]

Using my Indy's Volvo tester, I pulled a single code today:

ECC-422: Self Adjust Drvr temp motor failed.

I erased it, ran the adjust motors routine, it ran for about 20sec., then the two amber lights flashed, indicating a new code had been set. Again, it was ECC 422! Repeated this a few times and it's the same code set each time.

When I set air position & fan speed to AUTO, the ECC does attempt to regulate. When both drvr & pass temp controls are set to 100% HOT, the blower blows 100%. When both are set to say 72°F, the blower speed greatly reduces. However, the air is always directed out of the four dash vents and it's always 100% HOT.

While doing research, I found this:

The climate control module incorrectly detects the signal from the temperature damper motor position sensor.
The control of the temperature motors stops, the temperature in the passenger compartment cannot be
adjusted, the orange LEDs on the control panel flash and the Diagnostic Trouble Codes (DTCs) ECC211,
ECC212, ECC231 and ECC232 may he stored. The Diagnostic Trouble Codes (DTCs) for the position
sensors are therefore stored unnecessarily without there actually being a fault. This, in turn, causes an
abnormally large number of fault free damper motors to be replaced. Settings in the climate control module for
these Diagnostic Trouble Codes (DTCs) must be updated.

Any updating that is carried out means that the above Diagnostic Trouble Codes (DTCs) are not detected and
stored.

I suspect this is going on. Namely, that the CCM is incorrectly detecting a fault that's not there. Unless there is a wiring or connector problem with only this module.

I can hear and feel the air being directed to other areas when the test is in progress while driving. Yet it doesn't complete and the green LED continues to flash continuously.

The next step is to find a used damper motor, plug it in and see if the problem is resolved.

[sleddriver]

Update:

Well, I've hit a stone wall with this. I've been unable to find a known, good used damper motor locally. I was quoted > $175 for a new one however! And typically, electrical parts are not returnable. So if it DOESN'T solve the problem, I'm out the money.

My indy came out with his scanner, and verified my findings. He too was unable to get the dampers to calibrate. He suggested removing the motor from the damper, and seeing if it moves using the ECC temp controls. That won't work though as there is still a fault code set. Further, I can't look at the motor move, while driving the car, nor can I look at it while someone else is driving: The motor wiring harness is too short to bring it out from under the dash.

We looked at an air plenum/duct system removed from a car. To get 100% HEAT out (on both sides), the damper has to be rotated 100% CW on the driver side and 100% CCW on the passengers. When the motor is removed/disconnected from the damper shaft, the damper closes (falls down) due to gravity. My thinking is that this is the 100% COLD position, as the damper is now resting on top of the heater box, and thus "closed off" to air circulation.

So if I center the motor shaft within its range of motion and fit it onto the resting damper shaft (which is by default 100% COLD), the mechanical range of motion of the damper is going to be about 90°CW, while the electrical range of motion of the motor is starting off in the middle or 50% CW and 50% CCW. Perhaps this condition is causing calibration problems?

Perhaps I should set the motor shaft so that it's at its CCW limit, THEN install it. Now it'll have about 90° of CW rotation to fit the 90° of CW mechanical rotation of the damper shaft. Make sense? What do you think?

[sleddriver]

Update:

I decided to follow a hunch after writing out the above. I pulled the drvr temp damper motor, noted the damper fell all the way down due to gravity (no heat position). Then using a 9V battery, I rotated the motor to full CCW to match the position of the closed damper. (Previously I'd been installing the motor with the gears set in the middle of their travel, aligned with my index mark). Then reinstalled the motor and went for a warm-up drive.

After about half a mile, I could hear the dampers moving and feel the air moving from the floor to the dash to defrost. The drvr air temp went from COLD to WARM to HOT. The passenger air temp was now adjustable! The green blinking LED was gone! Air distribution was now back under operator control and so was passenger air temp. Drvr. air temp remained at 100% HOT.

Using my indy's Autodiagnos Multi-tester pro, I pulled the same, single code: ECC-422. I cleared it, then attempted to calibrate the motor positions. I could feel cold air come out of the drvr vents for a bit, then go back to HOT. The calibration ran longer than previously. However, it eventually failed. The blinking, green LED was back, along with its two amber friends. Once again, ECC-422 had been set.

So I learned that my above hunch was correct. I also learned that the ECC was able to move the drvr. temp motor, but it was having trouble receiving feedback from the position potentiometers. Since the ECC didn't know where its 100% CW point was (100% HOT), it left it there. Meaning 100% HOT. Since I'm able to read the resistance from the pots terminals, I will now check out the connectors, and wiring harness for a fault.

So, following my hunch worked! Kudo's to erikv11 and jimmy57's posts for pointing me in the right direction!

[sleddriver]

Update:

After my initial response at "restoration", I've been unable to repeat it. Now I'm met with flashing amber + green ECC lights. I've begun to trace each wire, create a connector pin-out + color code to measure the voltages put out by the ECC. The motor has spent quite a bit of time on my electronics bench and appears to work fine. Thus I'm now beginning to suspect connectors, wiring, or ECC.

There must be some trick to aligning the motor/damper combination when reinstalling. I hit it once...but only once. No joy since.

While doing some research in the 850 manual, I found some interesting items. The manual is written for a 95-96 850 with ECC. Some things match up, some don't for my 98 V70 T5.

First, the ECC puts +5V across the damper position pots, the voltage from the wiper is then used by the ECC to signal damper position. It varies from 0 to 5V. Testing the suspect unit on my bench revealed 0.1 to 4.9Vdc. Second, the manual stated that the wiper resistance should vary from 0 to 12k Ohms. Mine varies from 321 to 9k6 Ohms. The lowest I could get the min. resistance was 203 Ohms. I was able to measure a brand-new-Volvo-damper-motor, right out of the box. It's resistance varied from 278 to 9k9 Ohms. This is a bit "wider" range than mine, but there's not a lot of difference.

DTC 2-1-1, 2-2-1, 2-3-1, 2-3-3 & 2-3-5
DRIVER’S OR PASSENGER’S SIDE DAMPER MOTOR POSITION SENSOR CIRCUIT OPEN OR SHORTED TO POWER

1) Check if DTCs 1-2-2, 1-2-4, 1-2-6, 2-1-1, 2-2-1, 2-3-1, 2-3-3 and2-3-5 are present. If all DTCs are not present, there is an open or short circuit in a wire between ECC control unit and damper motor which applies to DTC. See AUTOMATIC A/C-HEATER SYSTEM DIAGNOSTIC TROUBLE CODES table, then go to next step. If all DTCs are present, an open circuit is present in common ground at ECC terminals A9 and A10. See Fig. 10.

2) Ensure ignition is off. Connect test unit between ECC control unit and control unit connector. Check ECC grounds. See DTC 1-2-1, OUTSIDE TEMP. SENSOR CIRCUIT SHORTED TO GROUND. Also check power supply to damper motor position sensor. See TEST MODE 2 under TROUBLE SHOOTING. If ECC grounds and power supply to damper motor position sensor are okay, go to next step.

3) Turn ignition on. Connect voltmeter between test unit pins No. 10 and No. 17 (driver’s side damper motor), No. 18 (passenger’sside damper motor), No. 20 (ventilation damper motor), No. 19 (floor/defrost damper motor), or No. 21 (recirculation damper motor).

4) If voltmeter indicates 12 volts, check wiring and ECC control unit terminals for a short to voltage. See PIN VOLTAGE TESTS under TESTING. If voltmeter indicates 5 volts, an open circuit is present in wire. Go to next step.

5) Ensure ignition is off. Disconnect ECC control module, but leave test unit connected to ECC connector. Disconnect 6-pin damper motor connector and install a jumper wire between connector terminals No. 1 and 2. See Figs. 11-13. Connect an ohmmeter between test unit pins No. 10 and 8. If ohmmeter indicates continuity, go to next step. If ohmmeter indicates no continuity, check for open circuit in Brown ground wire.

6) Connect jumper wire between damper motor connector terminals No. 2 and 3. Connect ohmmeter between test unit pins to test respective damper motor. See DAMPER MOTOR TEST UNIT PIN NUMBERS (RESISTANCE CHECK) table.
DAMPER MOTOR TEST UNIT PIN NUMBERS (RESISTANCE CHECK)

Pin No..........................Damper Motor
8 & 17 ………………………………. Driver’s Side
8 & 18 ……………………………. Passenger’s Side
8 & 20 ………………………………… Ventilation
8 & 19 ………………………………. Floor/Defrost
8 & 21 ………………………………. Recirculation

7) If ohmmeter indicates continuity, wiring to damper motor terminal No. 3 is okay, but an open circuit is present in damper motor position sensor. Go to next step. If ohmmeter indicates no continuity, damper motor position sensor is okay, but open circuit is present in wire between damper motor connector terminal No. 3 and ECC control module connector “A”.

Ensure ignition is off. Disconnect damper motor connector. Connect ohmmeter between terminals No. 1 and 3. See Fig. 11. Turn damper motor output shaft. Ohmmeter should vary between 0-12,000 ohms. If resistance is to specification, go to next step. If resistance is not to specification, there is an open circuit in damper motor position sensor.

9) Connect ohmmeter between damper motor terminals No. 2 and 3. Turn damper motor output shaft. Ohmmeter should vary between 0-12,000 ohms. See Fig. 11. If ohmmeter indicates no continuity, there is volvo 850 ECC climate control damper motor ac airco system connector connectors identifying an open circuit in damper motor position sensor. Replace damper motor.

If someone would post the updated directions from VADIS or VIDA, I'd really appreciate it!

[sleddriver]

UPDATE:

I've tested all the wiring from the ECC connector A to all four damper motors. Found no faults. I now suspect the ECC itself is the cause. Looking back over my notes, I remembered that while driving with A/C on Max Cold during the Summer, occasionally the ECC would turn the drvr. temp damper to 100% HOT, mess with the air dist. damper motor and sometimes restore them both back. Other times I had to turn the drvr temp control to full hot, then back to cold a few times, or turn the car off first. Very odd....

So given this past behavior, + the fact the DTDM tests fine on the bench, I suspect the ECC. I closely examined the PCB for bad solder joints, hairline cracks, and while I did find a few grainy joints, nothing else. I traced pin A12 backwards, but still have more to do. After 18yrs. I'm also suspecting the small SMEC's and the reg. elec. caps as well. I don't have a SMD rework station though and my soldering iron tip is too big to deal with these devices.

Anyone have to replace their ECC unit? Where did you get it from? Did it solve your problem?