1996 Volvo 850 ECC Errors after evaporator replacement

Redneck · Post by **Redneck** » 24 Jul 2014, 21:51

Hi,

I have a big problem. I have just finished putting the car together after replacing evaporator and fixing dashboard mounts. I was about to refill the system with freon and it looks like I have a problem with the ECC. I have ECC lights blinking and these are the error codes that I pulled out from OBD:

1-2-2 …… Outside Temp. Sensor Circuit Open Or Shorted To Power
2-2-1 ….. Pass. Side Damper Motor Position Sensor Circuit Open Or Shorted To Power
3-2-1 ….. Driver’s Side Damper Motor Active Too Long
3-2-5 … . Recirculation Damper Motor Active Too Long
4-1-4 …… Driver’s Side Temp. Sensor Intake Fan Seized
4-1-7 …… Pass. Side Temp. Sensor Intake Fan Seized
4-1-8 …… No Control Signal To ECC Power Stage
4-1-9 …… ECC Power Stage Emitting Faulty Diagnostic Signal

This makes me very sad after all that hard work. Please help if u can. Have you had similar error combination? I have also tried to erase all these errors but I was not successful. I may not be erasing them correctly. My hope is that the ECC has gotten confused and it just needs to be reset somehow.

Post by **Ozark Lee** » 24 Jul 2014, 22:52

Clear the codes and see what comes back. The codes get cleared in the standard manner, push the button for 5 seconds, release the button and the LED should light. Push the button again for at least 5 seconds.

Does everything work after the evaporator change?

...Lee

Redneck · Post by **Redneck** » 25 Jul 2014, 00:11

Yes, the car drives and everything else works except the ECC which means I can't refill with Freon. I got partial access to the cables behind the dash again by taking off the knee bolsters etc. and all cables look ok. Everything is plugged in.

There is one thing that makes me happy and think that the ECC problem may not be related to the latest work on evaporator and taking the dash/disconnecting/reconnecting everything. About a year ago I had ECC lights blinking and the error codes I pulled were exactly the same as this time (I found the piece of paper from a year ago where I wrote the error codes down at that time). I replaced the blower motor at that time because I thought it may be at fault, but that did not help. I looked at that infamous ECC blower resistor at that time and it looked fine. It looked fine today as well (still may be malfunctioning, but I don't see anything burnt inside). It fixed itself last time somehow just from me poking around pulling stuff and putting it back. Now the same problem returned with the same error codes. The only place I was messing around at that time were the cables and connectors around the blower motor. I have ECC unit now opened on my desk and I am looking at all capacitors. They look fine by visual inspection. I always spray every connection with contact cleaner before plugging it back so it reduces the posibility of an oxidized connector at least in those connectors that I disconnect and re-connect.

Well.. now I am thinking.. I don't remember if I cleared those error codes last year, so I may be reading last years error codes, but then, can the ECC work properly if the codes are not cleared? The ECC worked fine until my recent evaporator work

It is a bummer because I can't get the satisfaction from my evaporator and dashboard work until I can refill with Freon (It held maximum vacuum negative pressure for about 2 weeks or more:). As soon as I put the ECC back together I will attempt resetting the codes again. I am also recharging the battery now to be sure that low voltage is not causing it somehow.

Post by **Ben850** » 25 Jul 2014, 07:16

You have to clear the codes either way.

See what, if anything comes back. It doesn't fix itself when codes are stored. Trust me. I just finished resetting mine with my home made code reader. It works now.

If you still are using a unit with capacitors, I would change that out before the inevitable. It also may be giving you false codes.

Post by **Ozark Lee** » 25 Jul 2014, 07:25

I guess I'm confused. None of the listed errors should preclude charging the system unless the blower won't run at all. Even then it should charge but the pressures will get out of whack with no airflow over the evaporator.

...Lee

Redneck · Post by **Redneck** » 25 Jul 2014, 13:56

Ben850 wrote: If you still are using a unit with capacitors, I would change that out before the inevitable. It also may be giving you false codes.

Ben850, Do you mean change the capacitors within the ECC unit as a preventive maintenance?

For some reason, I can't clear the codes, and none of them seems to be correct. It looks like they are old error codes from many years ago that have never been cleared. I can't clear them by holding the button pressed for 6-7 seconds. Can you tell me your steps to clear the codes and the pins that you connect to?

Post by **Ben850** » 25 Jul 2014, 21:14

Redneck wrote:
Ben850 wrote: If you still are using a unit with capacitors, I would change that out before the inevitable. It also may be giving you false codes.
Ben850, Do you mean change the capacitors within the ECC unit as a preventive maintenance?

For some reason, I can't clear the codes, and none of them seems to be correct. It looks like they are old error codes from many years ago that have never been cleared. I can't clear them by holding the button pressed for 6-7 seconds. Can you tell me your steps to clear the codes and the pins that you connect to?

Not the capacitors, the complete unit. It sounds like the capacitors have gone already.
Being a '96 it should not be the old type with caps anyway. Someone must have changed it out before.

Either that or the capacitors you are speaking of are not the ones in question. Can you take a photo?

'95 through '97 were updated to a more solid state design that deleted said parts. One of those units is what you want. Then you should be able to clear codes.
You have to read ALL codes before you can clear them. You will know you have read them all when a duplicate comes up.

Redneck · Post by **Redneck** » 25 Jul 2014, 21:33

I read all the codes and it still didn't clear them for some reason. I think that all of the ECCs even the latest ones have capacitors. I don't think it is possible to have an electronic board as complex as the ECC without having a single capacitor. The capacitors looked fine, not bloated, but could be dried out to some extent.

Post by **Ozark Lee** » 25 Jul 2014, 21:49

You are pressing and holding the button twice aren't you? They should clear but you need to read all of them first and then clear them before you turn the key back off.

...Lee

Post by **jreed** » 26 Jul 2014, 05:53

I took a photo of the backside of the ECC board from my '97 855 GLT showing the electrolytic capacitors. I replaced these capacitors a year or so ago as preventative maintenance. It was working fine before the replacement, and it's still working fine now... it probably was not necessary. People with earlier versions of the ECC board have reported problems with burned diodes and capacitors in the upper left corner of the board.

: Electrolytic capacitors in a '97 vintage ECC

Regarding clearing the codes, as Ozark Lee said, after reading all codes you have to press and hold the button for about 6 seconds. Then after you release there is a pause and the light comes back on. Then you press and hold for a few seconds until the light turns out. Then you should have cleared all the codes. You can read them again at this point and you should get "1 1 1". If this doesn't work, there may be a problem with the code reader or more likely the ECC unit itself.