Help with ECC codes

T5R_Guy · Post by **T5R_Guy** » 11 Jul 2017, 10:47

Hi All,

Im new to this illustrious forum though I have been using it for quite a while. Im on my 3rd 850 but my 2nd T5r. This one being the beautiful Olive colour.
I haven't owned the car long and, as is the way, im working my way through all the niggles that the car came with. Anyhoo, at the A/C now. I have the flashing yellows by the knobs, so Using a home made flash reader (Instructions found on here btw) I found out the stored codes are:

1-2-4....Drivers side interior temperature sensor open circuit or shorted to 12V
1-2-6....Passengers side interior temperature sensor open circuit or shorted to 12V
2-2-1....Drivers side damper motor position sensor open circuit or shorted to 12V

Has anyone had these codes before and can guide me through a step by step to help me get rid. I live in England and at the moment we are getting a bit of a heatwave, so A/C would be amazing.

Many thanks in advance,

...Guy

Post by **scot850** » 11 Jul 2017, 11:24

If you have ECC (Electronic Climate Control) you should have a cabin temp sensor built into the grab handles attached to the roof above the front seats by the door. If you look at them carefully there is a round hole in the handle assembly and the temp sensor sits behind there. The sensor is a little wire thermostat that has a small fan behind it that draws air over the thermostat wire and sends a signal to the ECC to adjust temp accordingly.

Over the years, these fan blades get clogged with air borne crap like hair and dust and the fan stops working.

Usually these can be re-activated by removing the motors and cleaning the crap off the blades and spinning the fan. I clean the blade carefully with rubbing alcohol (IPA) and cotton buds and a small artists paint brush with a final spin using an air line. A few drops of silicon or light oil helps too.

To remove the motor, remove the grab handles (screws under 2 flaps that pop loose), then pull the door surround off that runs above the door opening and you can then access the motors by opening the gap between the body and the roof headliner.

Chances are the other issue is a failed servo motor above the drivers knee bolster. Requires removal of the lower dash panel on the drivers side, remove the 3 nuts holding the knee bolster in place and then contorting to find the motor above the left knee. If the RHD system is a reversal of the LHD it is a case of removing 3 small Torx screws to remove the motor and replace with a good scrap yard motor. There are 4 or 5 on the 850. Easiest one to remove is the main air flap one behind the glove box. ! or 2 screws and it slides out.

There have been threads here where folks have opened up the motors and cleaned them to get them working again
Neil.

T5R_Guy · Post by **T5R_Guy** » 12 Jul 2017, 10:19

Thanks for the help Neil,
Ill try to keep you updated as to how this goes. I've literally just got in from fiddling with the car. I examined the 2 sensors by the drivers and passengers grab handles and they were both not appearing to work when I turned the fan on. On closer examination they were full of crud. It looked like the roof liner sponge backing had got in there. This stuff does tend to fall apart on old Volvos. Anyhoo, a quick blow out and clean up with an alcohol soaked Q tip and now they both work lovely. I've still to address the motor but that's for another day.
Cheers,

...Guy

T5R_Guy · Post by **T5R_Guy** » 12 Jul 2017, 10:21

Another quicky,
the code that reads 'Passenger side Damper motor....' who's passenger side do they refer too? UK or USA?

...Guy

Post by **abscate** » 12 Jul 2017, 10:49

You can test that by turning on either heat or AC and then changing the temperature of one side - and seeing which one does not change temp.

I believe the ECC system in the UK is the same as ours - temperature can be controlled on each side, but the air delivery is the same for both.

Post by **scot850** » 12 Jul 2017, 14:57

Good question on the LHD/RHD warning info. One would hope it would be in relation to the driver's seat position in the country and the side of the car the steering wheel is located, but as our friend abscate says, try using the ECC unit to see what moves and what doesn't. I would expect though that the passenger side would relate to the LHS of the car. But I thought you said above it was the driver's side damper that was the issue?

If it is actually the passenger side, then there is a plastic sleeve that the servo motor slides into (an internal square section hole on the end of the damper shaft) that is know for snapping with age. Actually normally it splits so the motor cannot turn the shaft. The way many have fixed it is to use small jubilee/worm drive hose clamp to squeeze the 2 sides together. The part used to be available to buy and certainly on a LHD car, can be replaced without removing the dashboard but is fiddly.

Neil.

T5R_Guy · Post by **T5R_Guy** » 17 Jul 2017, 09:54

This weird. I had the heater blowing hot, turned to cold and they all turned to cold? I spose the next thing is to try to delete all the fault codes and see which ones come back?

...Guy

Post by **jreed** » 18 Jul 2017, 05:11

Yes, that's what I would try. If the cause of the error was resolved, the code will not return.