['96 850 GLT Wagon w/ECC] Feet still feel no heat

s2zeller · Post by **s2zeller** » 26 Dec 2012, 19:30

I have been having problems (nothing that I couldn't override by going to manual) with my ECC for quite some time (2009: 850 GLT Wagon - 1996 - Climate Control seems too cold; 2012: ['96 850 GLT Wagon] AUT gets hotter than it ought; [1996 850 GLT] Trying to diagnose climate control problem).

However, within the past couple of (cold Wisconsin December) weeks, we've been getting no heat to the floor (in addition to the other problems). We haven't been able to find any way around it.

I found this thread (No heat to the floor 96 850R with climate control) regarding the lack of heat to the floor in front. Following that discussion, I did find a split shaft on the damper motor to the left of the glovebox and repaired it with a hose clamp.

What was not clear to me - and what I am now having problems with - is knowing whether the motor should actuate when moving the center dial of the ECC, or if that only works when there is actually heat/cold to pump down there.

I'm thinking that it should do something when the center dial setting is changed, but it doesn't.

Prior to reinstalling the motor, I did ensure that I could manually turn the repaired shaft. So, I'm confident that that is not stuck.

I also used this link (Testing an ECC Damper motor Volvo 850) and found that the motor did in fact turn the shaft both ways (depending on how the 9V battery was applied). Is this a valid test?

However, once connected (again), the motor does not seem to respond to the ECC settings. I hear/feel the motor behind it move when the passenger-side temperature dial is changed, so some control is being exercised.

I should note that we get blinking REC/AC lights on every start up.

My wife tried to get the codes read at the most reliable (independent) Volvo repair shop in town, but they were getting a lot of things that did not look like ECC codes. The dealer shops are not usually that thrilled (or competent) about working on anything more than a few years old, so I'm not all that happy about going there.

Anything obvious that I should be trying (e.g. swap one of the other damper motors for the floor/defrost motor; buy a used ECC control unit)?

Thanks,
Scott

Post by **scot850** » 26 Dec 2012, 22:54

If I recall, the flaps are controlled by a servo motor on the RH side of the center consol, and under the dashboard. I'll not go into the details of how to get to it as it sounds like you have already been in there. I believe there have been posts on this before, but what usually happens is the little square end of at the end of the plastic flap that the square shaft that the motor fits into to turn cracks, so the motor works but the flap doesn't move. You can remove the end cover that holds the flap and slide the flap off and replace it. This is a common fault with 850's and the part is fairly cheap from the dealer. I found the cause of the failure of mine was partly due to the rubber flaps on both side being partly melted (?) or had gone sticky causing the flaps to stick. I had to replace both sides, but was lucky to get the LH flap from a breaker yard as it is not available new (you have to buy the whole box for Approx. $1000 from the dealer). I ended up removeing the whole dashboard and stripped the heater unit and replaced the 2 flaps as well sa the A/C evaporator (had never worked since I bought the car) and the heater core. Chances are all yo have to do though is replace the flap which means the dash can stay in place.

Hope this helps! Do look closely when the servo turns and there is a good chance you will see a crack open up as it tries to turn.

Neil.

Post by **Ozark Lee** » 27 Dec 2012, 00:46

There is also a procedure to recalibrate the servo motors on the system. Since the damper shaft split the system may not know what position the damper is in.

With the OBD-I it was fairly easy. VOL-FCR doesn't deal with the ECC on my 850s but it might on my S70, I will need to try it tomorrow and see since the S70 is home for winter break. I need to reset my daughter's service light anyway.

...Lee

s2zeller · Post by **s2zeller** » 27 Dec 2012, 05:52

@Neil:

The flap itself moves, and the shaft is now bound with a hose clamp. The servo motor itself is not turning when I change the setting of the center ECC console dial.

@Lee

A reset certainly sounds like something to try (didn't know that could be done).

Post by **jreed** » 27 Dec 2012, 07:11

I haven't tried the automatic self-adjustment procedure, so I'm not sure it works, but for what it's worth the Haynes manual outlines the following procedure:
1) Move fan speed control switch on ECC to any manual fan setting (not "O" or AUT)
2) Turn function selector switch to "AUT"
3) Use the diagnostic module ('93-'95) Socket 1 of Module B or home-brew LED code reader ('96-'97) and press the button four times for one second each
4) The LED should start flashing
5) Enter 9 9 9 9
6) Wait about 10 seconds to let the fan motor start up again
7) The AC and ECC lights should flash
8 ) Drive the car at >20 mph for a few minutes to let the ECU learn the new values of the dampers
9) Stop the car but leave it running to allow the ECU to save the new values
10) Verify the self adjustment procedure by pressing the diagnostic button 1 time for 1 second. If you get "1 1 1" flashed back, the procedure is complete.
11) If you get 5 1 1, it was not completed and should be repeated
12) If you get any other code, there is still a fault in the system that must be corrected.

s2zeller · Post by **s2zeller** » 27 Dec 2012, 09:52

Thanks, jreed. Looks like I need to go get parts for the home-brew reader (I just came across a number of your helpful posts) and see if that gets me to the bottom of this once and for all (or at least until the next thing comes up).

s2zeller · Post by **s2zeller** » 27 Dec 2012, 13:49

Before going off to get parts, I followed the first part of this thread (ECC climate control temp sensor measurements made easier) to check the internal sensors.

For my '91 Jetta, there was a temperature graph that corresponded to how a sensor behaved. Is there something like that for these sensors?

The reason I ask is that all of them are reading > 20k, and they should apparently be 8k to 12k. My garage is ~38 degrees F, so I didn't know what that would do to the resistance.

I'll be taking the car out now and warming the interior to see what that does to the readings.

s2zeller · Post by **s2zeller** » 27 Dec 2012, 15:10

After getting the car warmish (I'm guessing the interior was ~70, tho' it could easily have been 10 degrees colder), the cabin sensors were reading in the 15k to 18k range while the duct sensors were in the 7k-8k range. So, they did drop closer to the normal range.

I had left the ECC control console ajar from the center dash so that I could do the post-trip measurements. When I pulled the control console out, it was quite warm behind it. I was a little surprised since I have all of the vents open and had the temp set at around 74.

Anyhow, I'll be assembling the home-brew reader and see if anything interesting can be found out.

s2zeller · Post by **s2zeller** » 27 Dec 2012, 16:26

OK, I pulled the following codes (descriptions from 'ac system heater auto.pdf') in the following order:

134 - Pass. Side Duct Temp. Sensor Circuit Open Or Shorted To Power
141 - Driver’s Side Temp. Switch Faulty Control Signal
211- Driver’s Side Damper Motor Position Sensor Circuit Open Or Shorted To Power
221 - Pass. Side Damper Motor Position Sensor Circuit Open Or Shorted To Power
<blank>
222 - Pass. Side Damper Motor Position Sensor Shorted To Ground
231 - Ventilation Damper Motor Position Sensor Circuit Open Or Shorted To Power
233 - Floor/Defrost Damper Motor Position Sensor Circuit Open Or Short To Power
322 - Pass. Side Damper Motor Active Too Long
<blank>
<long blink>
<long blink>

The <blank> represents a 1-second click of the switch (like what precedes every other reading) followed by no blinks. After 10-15 seconds, I clicked again and would get a new reading.

Except for the final single <long blink> which yielded another <long blink> so I figured that was it.

I'll probably go through and verify again before I clear them out to see what re-appears.

Post by **jreed** » 27 Dec 2012, 18:03

Great work!
I have heard that the ECC unit never forgets an old code, so it might be a good idea to clear all the codes after you read them and then see which ones come back.