ECC Throwing a bunch of codes

[MagnificentSin]

Hello all,

I recently picked up a great condition 850 turbo sports wagon and I love the car so far but of course, it's got its fair share of issues. I already know my PCV system needs to be replaced (thanks for all the writeups they're very helpful) but one thing I couldn't find much on was the ECC system and repairing codes. Thanks to the writeup by AKJeeper I managed to read the codes, all 13 of them, and using the list he also provided I figured out what they all mean. Well kinda, that's where I'm stuck at. I'm not sure if searching for each individual code here on the forum is what I need to do but I'm struggling to find most of them, could anyone point me in the right direction on how to fix these codes (I'll list them at the bottom) or maybe they're all linked somehow? Thanks in advance

Here's the full list of all my codes... yay
124 Driver’s side interior temperature sensor open circuit or shorted to 12 volts
126 Passenger’s side interior temperature sensor open circuit or shorted to 12 volts
211 Driver’s side damper motor position sensor open circuit or shorted to 12 volts
222 Passenger’s side damper motor position sensor shorted to earth
231 Ventilation damper motor position sensor open circuit or shorted to 12 volts
233 Floor/defrost damper motor position sensor open circuit or shorted to 12 volts
234 Floor/defrost damper motor position sensor shorted to earth
323 Ventilation damper motor active too long
324 Floor/defrost damper motor active too long
325 Recirculation damper motor active too long
411 Blower fan seized or drawing excessive current
414 Driver’s side interior temperature sensor inlet fan seized
418 No control signal to blower fan power stage

[scot850]

Does any of the stuff work at all? Does the heater fan work for example?

The first 2 items are the cabin temp sensors in the grab handles above the front doors. To access them you have to remove the grab handles and the plastic trim above the door opening. This will give access to remove the sensor. It is basically a thermocouple and a small fan to pull the cabin air over it to sense cabin temp. They don't usually fail, but they get clogged up with all sorts of crap in the air over time to where the sensor can't draw air over it as the fan gets stuck. Remove and carefully clean with small artists brush and cotton buds with IPA. If you have access to a air compressor, once it is clean blow over the fan to check it is moving. You can add a small amount of silicon oil to the shaft but don't soak it, just a small drop.

Assuming the sensors have not burnt out with being jammed, chances are it will fix those 3 codes.

The rest will depend on the answer to my first question.

Neil

[MagnificentSin]

Does any of the stuff work at all? Does the heater fan work for example?

Thank you for your help, I will try and clean out the cabin temp sensors, I saw a video somewhere that showed how to do it so I should be able to do it early tomorrow.

As for the first question yes the entire unit works but very minimally. I can adjust the temp and it changes from hot or cold, however, the fans only appear to be working at a very low speed, blowing air out of all the vents simultaneously (might not be all but its at least coming out of the vents aimed to the face and the windshield)

If I remember correctly when I bought the car the guy mentioned something about recently doing work with the ac system and recharging it and I'm not sure if he said he replaced the actual ECC unit, could be completely wrong on that though.

[scot850]

It is weird that you seem to have nearly every possible code showing. This leads me to think that there may be a common issue affecting this and it is possible the ECC unit is faulty.

Not knowing your level of comfort in repairs makes it a little difficult to throw stuff at you. If you have even a little level of comfort, the first thing I would suggest is removing the ECC unit and check that the connectors of the 2 or is it 3 connectors have been refitted and pushed fully home.

Now to do that is not too difficult.

1) First, do you have your radio security code (Assuming it is still fitted with a Volvo radio/head unit? If not you will need to get it
If you have the original drivers handbook it is sometimes written into the back page or a business card. If not, and you don't
have it we can help you there too. But you need that to remove the radio fully. It may be possible to remove the radio but not
disconnect it if the wires are long enough. The reason we need to remove it is to get to the ECC unit base to detach it.
2) To remove the radio you need a narrow blade like a screw driver. There are 2 tabs, one either side of the unit. They have to be
pushed in slightly until the click and then they pop out proud of the surface. They often need to be pulled further out and that
releases the head unit allowing it to be slid out from the console.
3) If the wires are long enough you may be able to slide it out enough to allow access to the ECC unit base. BE WARNED. Wear a
pair of gloves for the next part. There are sharp edges under the ECC unit and the head unit hole. There is a metal tab under
the middle of the ECC unit if I recall correctly that either needs to be depressed or pried down to release the unit. The units if
they have been in there for a long time will fight to be removed. That is where the gloves come in. Try rocking the unit up and
to help it come loose and it should then push out from the dash. Check the connectors at the back are all fitted and pushed fully
home.

If the cables are all pushed fully home then we can move on from there.

Neil.

[MagnificentSin]

Alright I got the sensors above the handles cleaned, they were very dirty and cleaning them seemed to make the fan speed work now instead of being on only partial blast.
I am fairly comfortable working on cars I've always worked on my own cars so I know my way around so feel free to throw whatever at me
I removed the unit and used some compressed air to blow out all the connections but still have a few codes, otherwise to my surprise most of them disappeared
The codes still on the reader are as follows:
124
126
231
233
Then after that they just repeat, maybe disconnecting and reconnecting the main unit helped? No clue where to go now but 13 codes down to 4 is a good sign I hope.

[scot850]

Well we have progress! Now we are getting to the possible issues. Can't recall what you have to do to reset the codes on a 850 of your year. I am not sure if you have to use a VAG-COM cable and Vol-Fcr software is correct for your year to reset. I would suggest having them cleared and see if they return so we are not chasing ghosts.

The first 2 codes are the cabin sensors again, and if they are cleaned and working now, I can't recall if they have to be hard reset rather then self resetting.

The other 2 (231/233) could be genuine. There are a couple of faults that affect those particular items so if we can start with a clean code sheet and see what returns, then tackle those. The last 2 are potentially a fair amount of work, so let's make sure they are genuine.

Neil.

[MagnificentSin]

Alright, I'm about to head out and clear the codes, but before I do the car came with some extra goodies and after searching around trying to identify what some of the parts are it looks like I got a Blend Door motor actuator, not sure if that would be something I would need but it seems like something to make note of, ill post another reply after I come back in from resetting the codes

[scot850]

if I recall all the servo motors are the same. There is an issue with the blend motor, well not the motor but the blend flap on these cars. If you look at the motor you will see the motor shaft is square. The common issue is not the motor but the plastic end of the shaft. It cracks so although the motor turns as it should, the flap doesn't. If the crack is not huge usually a small zip-tie around the end of it pulled tight will get it going again. The part can be replaced but not sure if it is still available any more. The other issue I had was the blend flap foam seals melting and seizing the flap. That is what often causes the plastic end to break in the first place. That part is no longer available.

To get that sorted requires pulling the whole dashboard and heater system to get access to the flap. If it is not damaged, then cleaning off the old seal material and finding something suitable to replace it is do-able.

Neil.

[MagnificentSin]

Alright I just went and circled through the codes, same 4 as my previous post, clearing and restarting the car sends back the same 4 codes, where should I start with those then?

[scot850]

If you look at my last post I suggest what to check on the 233 code for the blend motor.

I am not sure if 231 is the cold air intake for the outside air. The damper flap for that can get blocked with crud if no one has fitted the later V/S70 cabin air filter holder into your 850. If it has not been fitted there could be a bunch of crap in the cold air flap. This will require removal of the glove box and cabin fan to check this.

There is a second issue which is the motor may have failed, but more often it is a small plastic arm that runs between the flap and the servo motor that breaks. I believe the part may still be available and it also used in the V/S70's. Make sure when you try to fit the arm that the motor is in the correct position. Changing the dash controls for re-circ will open close the flap so you can get the position correct. It can only be fitted one way and work!

Not sure why the 2 temp sensors are still showing an issue. Can you hear their fans running?

Neil.