AC compressor clutch doesn't engage

Volvo Kush · Post by **Volvo Kush** » 31 Jul 2016, 15:20

Hi,

Short version:

A/C clutch only engages when I start the engine (even with A/C switch set to off) but kicks off in a few seconds. Can force it on by overriding the relay with a paper clip.
Gap between clutch plate and clutch body: a tight 0.63mm.
Fresh refrigerant, pressure OK.
CCM codes:
CCM-001F air quality sensor: Signal too high
CCM-0020 air quality sensor: Signal too low
CCM-0004 compressor: Faulty signal

So far I tried:
- using a neighboring identical relay (from front AND rear window washer?) - no improvement.
- reducing the gap to a tight 0.5, 0.4 and 0.3mm using steel zip ties and bread clips - no improvement.
- tapping on the clutch plate with a stick (engine and A/C on) to force it to close and kick in - heard the clack between two parts but clutch did not engage.

Slightly longer version:
Last month I recharged the freon in my Volvo XC90 2003 T6 because the AC was getting weaker.
I paid a little bit more than usual (~180$) for it because the service included a free freon recharge if there is a leak / other problem with the AC system if I'm doing all the repairs at this shop.

I drove the car for a week until the AC started to act funny, blowing hot air at times until it died completely.
I returned to the shop, they used a black light to check for leaks and didn't find any, checked the pressure too and said that it was full. Their mechanic said that the compressor unit isn't engaging at all. We checked the relay and it was fine (I used the washer relay from nearby slot which is identical).
After scratching his head for a while, the mechanic removed the relay and stuck a bobby pin in there, completing the circuit. The AC engaged and started to blow cold air again.

Now the interesting part:
Seeing his "success", another sketchy looking mechano (the boss?) came out and started speaking Italian to the first one, presumably asking about the progress. After receiving the response, he told me that the problem is unknown and that they must take the car for the thorough inspection. He said that it would cost me 50$ to read the codes (even though I had my codes read for free in any other location!) and if they are unable to find the easy solution through the codes, they would need to spend several hours on the car's electrical system (69,99/hr) + the labor. I'm 24, but I look even younger, so I wouldn't be surprised if they tried to rip me off...

So my question is:
I there anything I can do myself to try to fix (or at least troubleshoot) this problem as I would like to avoid any further services from this place, because I feel like I'm forced to fix the problem at their shop if I want to keep my free freon recharge?

EDIT 1: I forgot to mention that in the process both mechanics used a multimeter(?) to check for the connection between each of the holes and random bolts near the engine. One of the holes did not light the lamp on their tool and they seemed mildly concerned about it, although they did not point it out as a problem.

EDIT 2: The clutch does engage when I start the vehicle regardless on whether the AC is on or off(and blows cold air in the cabin), but kicks off in a couple of seconds.

EDIT 3: Measured the gap between the clutch plate and clutch body, it was a little over 0.63mm.

UPDATE 1: Tried to fix the gap using stainless steel zip ties, bread clips and the combination of both to achieve a tight 0.3 , 0.4 and 0.5mm gap but didn't see any improvements (Pictures: http://imgur.com/a/kJUiu). The clutch still engages exclusively when I start the vehicle (even when A/C is off) but kicks off in about 5-10sec.

UPDATE 2: I had my CCM codes read!

CCM-001F air quality sensor: Signal too high
CCM-0020 air quality sensor: Signal too low
CCM-0004 compressor: Faulty signal

Screen picture here: CCM codes XC90 2003 - Album on Imgur

Thanks in advance,
Dmitriy

Post by **JDS60R** » 31 Jul 2016, 15:25

Measure the gap between the clutch plate and clutch body. You likely need to remove a washer. Report back on what you found. 0.3mm is the spec

Volvo Kush · Post by **Volvo Kush** » 31 Jul 2016, 16:13

Thank you for the reply.
I'll try to get a spark plug feeler gauge tomorrow morning.

Please see EDIT 1.

Volvo Kush · Post by **Volvo Kush** » 01 Aug 2016, 16:24

Hi, I checked the gap:
I used the 0.55mm and it slid right in, so I tried the biggest blade I had (0.63mm) and it wasn't even a tight fit. So I guess this is my problem?

See EDIT 2

Post by **oragex** » 01 Aug 2016, 19:21

I think 0.6mm is too large. Got to be around 0.3mm. You may upload a picture to let us see
I don't know how it goes on the XC90 but on my S60 here's how the job looks like
There also a quick fix http://forums.swedespeed.com/showthread ... clutch-fix
If the car has over 120K miles, I'd also check the a/c pulley bearing for friction noise, it gives up about same time as the clutch gap, easy to replace while working on the clutch

Volvo Kush · Post by **Volvo Kush** » 01 Aug 2016, 20:18

oragex wrote:I think 0.6mm is too large. Got to be around 0.3mm. You may upload a picture to let us see
I don't know how it goes on the XC90 but on my S60 here's how the job looks like
There also a quick fix http://forums.swedespeed.com/showthread ... clutch-fix
If the car has over 120K miles, I'd also check the a/c pulley bearing for friction noise, it gives up about same time as the clutch gap, easy to replace while working on the clutch

Hi and thank your for you reply!

The layout and the compressor itself look almost exactly as in this video (fast forwarded for you to min 7). There is a small access door behind the passenger's wheel, but I have never seen anyone using it.
The car has over 280k km on it (~175 000 miles).

Volvo Kush · Post by **Volvo Kush** » 01 Aug 2016, 21:02

I will attempt the zip tie fix in the following days. Can't see myself doing it from up top, hopefully the access panel will give me enough room to play with.

Post by **songzunhuang** » 01 Aug 2016, 23:07

I did the zip tie fix on my V70T5 and so far it's been working well after almost a year. So, yes it's a quick and dirty fix that just may do the trick for quite some time. Our XC90 hasn't had this issue yet, but it's a newer car by 5 years and over 125K miles.

Volvo Kush · Post by **Volvo Kush** » 02 Aug 2016, 10:44

I'm thinking about going with stainless steel zip ties. Any thoughts?

Post by **songzunhuang** » 02 Aug 2016, 19:34

Should work, but I do think it's a stopgap. Stainless won't make it any better. In fact if it's thin, you may not get enough change to close the gap. I used pretty thick plastic ties.

It's worked a few years but I fully expect to have to remove the compressor clutch and space it out properly one day.