99 V70XC - ECC Confused, Owner Confuseder

[RReese]

Thank you all. Have searched forums, not finding my problem, or one that offers solution. Really appreciate any insight on this somewhat tired subject!

1999 V70 XC. ECC "stuck" on panel and defrost position. Rotating selector will not change air direction/flow. In reading posts, this seems a fairly common problem.
I have:

• No flashing lights

• Temperature adjustments work

• A/C works, blows cold, and AC comes on when set to defrost

• "Auto" works, cycles fan high/low to moderate temperature

• Car has three actuators, not four (not one @ left of glovebox)

So far:

• Replaced ECC Module with known working unit from 2000 V70XC - No change

• Checked actuator - found actuator directly at left of console inop (was momentarily excited)

• Replaced actuator motor with known working unit from same '00 V70XC - turned on ignition AND!...Air selector adjustments worked - momentarily. Went through about 3 cycles of moving to different positions (watched arm moving on newly installed actuator). Then it quit again. Unplugged motor, re-plugged in motor - it functioned perfectly for again about 3 position movements then stopped. Whaaa? On a whim, unplugged, plugged back in (old motor), turned on key and same result - about 3 changes (motor hanging, not mounted) then stopped. Tried "new" motor again, same result, functioned about three times. Noticed not much coming from foot area, closed panel vents, unplugged-plugged... this time about 6 position changes and strong blowing to feet, but then same result, stopped at (I think) panel and defrost setting.

So, both motors function ('00 motor runs more smoothly). I still have no flashing lights to indicate a fault. Something stops the signal between the control module and the actuators?

Thank you so much for any ideas!

[RReese]

By the way, I have been "here" since 2014, but couldn't get the old sign in to work. My apologies to the admins!

[wizechatmgr]

Have VIDA? It will tell you the position of the actuators and if one is currently coded (locked out? so to speak. I believe, but am not certain, that certain codes would have to be erased by VIDA in order to reenable the stepper motor in question to change position. If I remember correctly, that one that handles direction/output spins a big wheel and you can hear it click as it turns during normal operation.

Sometimes the A2D converter blows and it cannot tell position anymore.

[RReese]

Thank you, I have a VIDA, but it has always been difficult to use, will have to revisit - and install it on a laptop I can take to the car.

Would there be codes with no flashing lights on Module? I suppose I'll have to check.

While I've got you here (and thank you), do you have a source for a VIDA you recommend? Mine has been difficult to install/access and response from the seller has been slow or incomplete.

[wizechatmgr]

Most versions that you can find I.E. 2014D will require a small patch as the resellers had it expire and didn't seem to feel like fixing it.

I believe we have a small VIDA sub-forum here that would likely end up with a good link.

[abscate]

You have to be careful with the 1999 and ECC control unit.

Paraphrasing Expert jimmy , it’s possible to get stuck in ECC hell if the unit and actuators get out of synch,

I’ll try find his post on this

[wizechatmgr]

You have to be careful with the 1999 and ECC control unit.

Paraphrasing Expert jimmy , it’s possible to get stuck in ECC hell if the unit and actuators get out of synch,

I’ll try find his post on this

Do not do the actuator learn procedure running - it WILL brick it.

[RReese]

Thank you Wizechatmgr & Abscate. I will search for that VIDA sub forum.

Meanwhile, there has been a temporary cooling of the "ECC Hell." I'm not sure what we did - or didn't do (probably the latter).

We showed up prepared to perform some reset voodoo - you know, key in position, unhook battery cables, turn slowly three times counter clockwise while chanting the names of the three highest Swedish peaks - but apparently the car just needed an overnight to think about the new actuator (which we very, very carefully installed in the same position that the old "frozen but not really frozen" one came out in) - as with no more input from us, with just a "let's see what happens this morning" turn of the key - the unit's functioning perfectly. Go figure. I wish I had a definitive answer for anyone searching this same problem, but I will endeavor to get a good VIDA hooked up to it and see just what's going on.

Then again, in the next day or two we might be right back here if it quits again!

Well, actually I will be in the neighborhood a while longer, as during this operation we also swapped driver seats from the donor '00 V70XC, and after enjoying a game of "How Does this Electrical Connector Disconnect?" - it functions perfectly, but now the SRS light is on. So far, in searching here, it looks like that's gonna take more than voodoo to reset.

[RReese]

You have to be careful with the 1999 and ECC control unit.

Paraphrasing Expert jimmy , it’s possible to get stuck in ECC hell if the unit and actuators get out of synch,

I’ll try find his post on this

Thank you! I'd love to learn more about this issue, because I'm sure I'll be revisiting it - can't believe I stumbled into a fix that will last long. I'll poke around for that post as well.

Since I wasn't aware of this issue, it sounds like I lucked out - but I did pay very close attention to the position of the old actuator, and made sure the "new" one was identical when the it was installed.

[abscate]

If you fire up the electrical system with the seat disconnected it will srs code. You need VIDA or a high end scanner to clear that code