1996 854 ECC top vent problems

[Klausc]

After tearing out my dash, fixing the vent control for the dash vents (completely closed and jammed) and repairing the floor vent with its broken plastic shaft, something is weird.

I put the key in position and cleared the codes, it came back 1-1-1 !!! I was at least expecting to go into mode4 and 9-9-9 to reset the damper motors. Quite pleased, I did a run to the supermarket where the interior heated up to 90F+.

When I restarted the engine, the blinking lights did not. But, the dash vents closed! It is like the polarity is backwards which is not possible due to the plug. Or is it? Vent control and blower speed are set to auto and now the blinking lights are back.

I am going to drop the SRS kneebolster and take another look at the motor. Also to re-open the vent.

I am open to suggestions, PLEASE! I want to add R134a and see how fast the evaporator leaks...

[Ozark Lee]

It is possible for the damper motor to be 90 degrees off depending on where the damper was actually positioned when the motor was removed vs where the motor thought it was positioned.

...Lee

[Klausc]

You are as confusing as the ECC system, but I understand.

When I removed the motor with its 90degree toothed wheel, I forced the dampers down so they would be in the full open position. I then took the motor apart and matched the toothed wheel so it would also be in the full down position. After reassembly, I moved the vent selector switch to dash and the blower to max. I got air out of the dash vents.

So, with the outside temps around 90F, why did the motor close the vents? It should have tried to open and found that the limit was reached.

Because of the heat inside the garage and lack of air movement, I am postponing lying on my back with sweat dripping into my eyes. This is a PROJECT, not my daily driver that has to work.

I might try positioning the flaps in the center of movement, and make the corresponding position for the motor and see if that helps. What bothers me is that the junk yard donor car had the flaps in the same position - stuck closed, about an inch too far. The only way to get the flaps to move is to take off the center vents and stick a bent rod down the hole (motor not attached) and shove hard.

If it is a motor problem, I might have to find a 1998-2000 donor and hope it works, no refund.

[Ozark Lee]

Are you in the AUT mode?

In the automatic mode the unit makes all kinds of goofy decisions based on a super secret algorithm that takes in data from the outside temp, cabin temp, sunlight, the speed of the car, and I think it even factors in the phase of the moon. I guess the real test is on the manual modes - does the air go where it is supposed to go when the various modes are directly selected?

...Lee

[Klausc]

When I cleared the codes before start up, they actually cleared. So I moved the blower to auto. I never got a chance to check all of the different vent settings before the dash vents closed.

It took me forever to fix my 1994 854T and only 8 years later, I forgot what I did!!

It is supposed to be 5 degrees cooler tomorrow, perhaps I can get to it in the morning. I have to be careful as I already broke off one of the motor mounting tabs. If I break another tab I will be forced to go to the pick&pull.

At least the motor for the floor/defrost vent is now working properly.

[mercuric]

I think it even factors in the phase of the moon.

Right?! And maybe a few exoplanets in galaxies far, far away, inhabited by angry beings that do not like humans.

You can operating the motor electrically with any sort of power source, 9v battery works, or whatever else. Doing so will allow you to see the actual limits of the motor travel. It's not a bad idea to make sure it operates the damper completely by manually applying power before putting the harness back on the motor. Also remember the stupid thing uses a slide on a resistive trace inside the motor case as a position sensor, they can get contaminated with grease from the gears and the ECC ECU will be completely confused, eventually throwing "active too long" codes after a few days.

I got somewhat frustrated dealing with the POS and just rotated the dampers where I want and disconnected the motor. I'll deal with it later in the fall/winter when it's not so hot, I hear you on the sweaty mess. This sort of stuff is too annoying to do in the heat! It's on the list of fun for the fall/winter. Once its cool I'll drive my no-AC beater wagon for a few weeks while I do a bunch of stuff to the 850.. Maybe even have the cash for some go-fast parts by then >:)

[Klausc]

Mercuric,

Interesting about the grease on the potentiators (sp?). Both of the motors I disassembled had grease on them. Should that be completely removed? I had thought that a light coating of dielectric grease would be good for better contact.
The motors move in both directions with a 9V battery, depending on the polarity.

I am about to take out the vent motor and reposition the dash vent to half distance, move the motor gear to the same place and try again.

All of the other dampers are in the closed position, which is where I assume they should be given the ambient temps and the AC not running. I guess I should also check the codes again before I crawl under the dash.

[Klausc]

Darn, another step backward. I removed the dash vent damper, unstuck the closed vent, opened up the motor and cleaned it out, positioned the 90 degrees worth of teeth to the marks on the motor, put it back in the car.

I ran through the mode 4 procedure and it did not complete, of course. Now I have a 5-1-1. That's easy to do again.

But I also have 2 additional errors:
2-3-1 = Vent damper motor position sensor open circuit or short
2-3-3 = Floor/defrost damper motor position sensor open circuit or short

Thanks a lot, ECC. What do you want from me? More sweat? I am tired of taking the motors out and repositioning them, the silly T15 screws are hard to get to.

At least the dash vents are open and the floor is closed. Nothing else works on the dial, except recirc switch.

Time for an ice bath.

[abscate]

It would be fun to take a peek at the code that runs the later version ECC. The 1999 version even has a subroutine that turn the fan blower on for 4 minutes, 60 minutes after shutdown, to dry the AC evaporator and prevent mold.

I hope I havent caused the OCD on this Board to go sit in their cars for an hour now. You know who you are....the kind who get high anxiety reading......

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[Klausc]

Thanks for the 'bump'.

I am wondering why I was able to clear the 2 codes after I replaced the dash. The ECC unit was unplugged, is a good possibility. Of course the battery was also disconnected for a few days.

So, if I remove the glove box and reposition the floor/defrost damper and motor, with the ECC out or battery disconnected, I might be able to delete the two codes????

I will try again tomorrow or Saturday depending on my wife's schedule of my other duties around the house.

Good thing I never screwed the glovebox back in, saves a lot of time. Of course, the driver's knee bolster will stay out for the duration.

Any suggestions from all of you are welcome and helpful...