1996 854 ECC top vent problems

[Klausc]

ARRRRRGH I need a handgranade!
I disconnected the battery, cleared the codes - all of them- and went for a Mode 4 9-9-9 run. When I stopped and moved the key to position I for the supposedly 2 minute wait, the lights blinked!!

Now I get a 2-1-1 for the Driver's side damper motor position sensor open or short circuit. Still have the 2-3-1 and 2-3-3 for the other two vent motors. Plus the 5-1-1 for the mode 4 not working correctly.

Do I need to get a manual air box from the junk yard and trash mine? The 2-1-1 moter is behind the cruise control servo for the gas pedal and not easily accessed or seen.

[combatkarl]

Getting a manual airbox... I was wondering the same thing. Would this mean replacing the ECC dash unit with a manual climate control unit? Can this be done? While electronics are great, it seems they can be very expensive and difficult to fix. I'm curious to see what more experienced users say (as I'm a rookie Volvo owner). I've seen youtube channels (Scotty Kilmer) where the electronic controls are by-passed with a manual switch. But maybe passionate Volvo owners don't do things like this...don't mean to get off topic or offend anyone. As I said I'm a rookie Volvo owner - so I'm still learning, but do really appreciate this site. Thanks everyone for their time and expertise.

[Ozark Lee]

The manual and the ECC climate units are completely different from each other and you can't mix and match things between the two. If you are installing a MCC unit into a car that had ECC you do need to swap the controls to cable type controls and you also need to change all of the wiring to the fan and the blower resistor. As a part of that wiring change you will need the max fan relay and its socket. I would strip out everything electrical between the controller and the fan from the donor car. The fan itself is the same.

...Lee

[Klausc]

The white plastic air channeling box would also have to be swapped out. Not something I really want to do. Besides spending hours at a Pick&Pull and hours at home to remove the current system to get a system that I have to manually adjust, I would prefer to get my system running.

I got this car with the blinking lights and a broken shaft for the floor/deftost damper. I thought it would be a relative easy fix. Well, that part was! I expect it has been broken for a very long time and now it doesn't want to come to life.

The little motors work with a 9V battery attached to the outside poles, so why don't they work when they are plugged in???? I cannot afford new motors and I don't know what I would get at a P&P. Our local P&P doesn't have many examples to sift through.

[Klausc]

The ECC is regressing!
When I bought this car, I checked the ECC codes:
2-1-1, 2-2-1, 2-3-1, 2-3-3, 3-2-2, 3-2-3, 3-2-4, 3-2-5, 4-1-1, and 4-1-8. I laughed and cleared them, which resulted in an immediate 2-3-1 and 2-3-3. So I worked on those 2 dampers and motors.

Now, after tying to 'learn' the motor limits (9-9-9), I also get 2-1-1 and 3-2-4.

2-1-1 is Driver's side damper motor short circuit or short.
3-2-4 is Defrost/floor damper motor position short circuit to ground.

Is this really a motor problem or is the ECC unit failing?

[Ozark Lee]

Historically, when the controller fails it fails in a big way that involves a blown up capacitor and a charred circuit board. While that doesn't mean it can't fail in a piecemeal fashion, it would be unusual.

Have you tapped the motor wires with a voltmeter to see what the controller is sending out?

...Lee

[Klausc]

I took off the floor/defrost motor to check it out. All looks good. The vent was in the wide open position and the brushes under the white wheel look clean and good. There are 5 wires, 2 are 12V and move the motor back or forward depending on the polarity supplied by the ECC. The other 3 must be position sensors measuring resistance.

The stop limits are not electrical, per se, but physical. The white wheel driving the damper is capable of 180 degree movement, but the damper can only move 90 degrees. This movement is what is probably recorded in memory by resistance values. The picture is with the white wheel in the full defrost mode:

Floordefrost in closed pos.JPG (51.65 KiB) Viewed 701 times

This is what you find under the gear wheel. The electric motor is under the board, top left. The 3 gold sensors travel in the black strip area

Damper motor

Dampermotor.JPG (14.83 KiB) Viewed 701 times

[Klausc]

Dried grease was cought between 2 of the gold sensors under the gear wheel, inside the motor box. This was probably the "position sensor short to earth" error. Cleaned off with a soft toothbrush.

NOW, assuming that the motor works properly, how does one put the motor back on the damper vent?

Do I 'set' the motor in the center of the movement range? And then attempt to center the damper in its range of movement? Note that the floor/defrost damper closes (defrost mode) when the motor is removed.

I will need to 'set' at least three(3) vent motors, I hope that they all get seated in the same fashion. The floor/defrost is the only one that I can see with a flashlight, the other two do not have any possibility of line of sight - both of those are on the driver's side.

How do they set up the air box at the factory? And how do they then 'learn' the ECC?

[Klausc]

This is when maintenance history would be nice to have. When I went to Mode 4 to 'learn', the driver's side damper made an awful 'crack' noise and the learning stopped. I think the plastic connector shaft might have broken.

Obviously, the learning program is a set cycle and and once an error happens, all learning stops.

I still have to check the ground wires, whereever they are. The 850 pdf is very nice, but assumes that we all have a test unit. So where is pin 8? pins 10-21? In real life.

The motor checked out just fine. I am assuming that the white resistance wheel needs to be in the center of possible movement and installation requires the damper to also be close to center.

It still is puzzling to me why I can clear the codes only after removing battery power to the ECC unit.

[Klausc]

I am going crazy here. I am now assuming the ground for all of the position sensors is bad. The 850 pdf tells me that "open circuit is present in common ground at ECC terminals A9 and
A10." That's nice... A9 and A10 are the two brown wires. I have no idea where A10 goes. Is there a ground for the ECC somewhere that I can check?