1996 854 SE 2.5, Multiple ECC issues (with fault codes)

[granite]

Ok...
I reset the fault codes and NONE came back! Got a plain 1-1-1 afterwards. I even checked twice to make sure. And the orange flashing lights on the ECC panel are gone as well.

What's strange is that the whole thing seems to function properly now. Should that even be possible? I now get air from all vents as expected. Can clearing the fault codes restore functionality?

I still don't know if the AC works, though. It's only 5°C/40°F outside.

[abscate]

I think they inhibit AC function at 0C, so going to max cool should cycle the AC compressor and engage the clutch. Thats great news on clearing the codes, and could be all that you needed!!

[Ben850]

When I had made this code reader, I had also read codes from five different ECC units to see what could be useful.
Most important is still to read all the codes and then clear them.
As jreed had mentioned, it is a good idea to open the case. If you se a few smoked capacitors, it would be clear.
https://www.matthewsvolvosite.com/forums ... 37&t=60660

[Ben850]

Ok...
I reset the fault codes and NONE came back! Got a plain 1-1-1 afterwards. I even checked twice to make sure. And the orange flashing lights on the ECC panel are gone as well.

What's strange is that the whole thing seems to function properly now. Should that even be possible? I now get air from all vents as expected. Can clearing the fault codes restore functionality?

I still don't know if the AC works, though. It's only 5°C/40°F outside.

I had figured you might have had codes set abstract, or abscate? {Smile Steve!).

Either way, you may need to put a gauge on the A/C to find its viability. Depending on the outside temperature, you may set the unit to aut. with the settings all of the way cold. Fan speed to full, and see if the orange lights blink again.
If they blink, read the codes again, and you should find out for sure if there are any remaining issues.

Good wishes.

[granite]

I've done that (aut, full cold, full fan speed) and the blinking lights have not returned.

Today was marginally warmer, and I'm pretty sure now that the air is not being cooled. I compared it with the AC of a car I drive at work, when both were at the same outside temperature. The air coming out of the working AC was definitely cooler.

Next step is then to check if the AC compressor engages or not. Is it possible to do that without removing stuff? It doesn't seem to be that accessible, but if there is an easy way to check if it's running or not, I'd love to hear about it.

[abscate]

You just look at it. When the cluctch pulls in you will hear a big click, and the inner part of the pulley will start turning with the belt driven part.

[granite]

I had a quick look today, and the compressor pulley doesn't turn. No sounds either. I gather that it's most likely either a low pressure warning (i.e. empty system) preventing the compressor from turning on, or a worn clutch. I'll check the clutch gap later this week. If it looks all right, and given there's no click sound, I suppose the stuff has leaked out.

[abscate]

You can jump the low pressure switch with a paper clip to see if the clutch pulls in. That will suggest low pressure and confirm the clutch operation.

[granite]

Had another peek at it a couple of hours ago.
The clutch gap is huge. 1.2-1.5 mm or so. That's about four times too big, right?
However, I don't think that's the issue. I started the car and set the ECC panel to make the AC turn on, and then used a wooden stick to push the clutch inwards. It touched, but never engaged. So something is preventing the AC compressor from starting.

Next step is to jump the low pressure sensor. I think I've found it, but I'm not sure how to disengage the metal clip holding the connector. It was a bit too dark outside (I don't have a garage) by the time I had finished testing the clutch, so I couldn't get a good look at it.