2003 S40 with intermittent AC issues

MLS1965 · Post by **MLS1965** » 02 Sep 2016, 15:33

My 2003 S40 has developed an intermittent AC cooling issue. More often then not when I select the AC button nothing happens. It continues to blow warm air. Once in a while it will work and blow cool air, but not ice cold as it did when I bought it used in 2005. I replaced the Climate Control Module from one I purchased on eBay and it work fine for a few years. Then it failed again. I bought another CCM on eBay and it didn't fix anything. Luckily it was a money back sale so I just requested my money back. I bought a second CCM and now it only will work intermittently. What the heck is going on..? The AC pump is new and fully was Volvo Dealer serviced..it frozen in the middle of all of this and I thought it was my fix. It wasn't. I've read that the thermistor inside the CCM can go bad, but also I've read that changing out a CCM requires a shop computer calibration..? What is your best guess as to what the issue might be. I can buy a brand new CCM for close to $800, but that's a lot to send without a promises it's the fix.

Post by **alschnertz** » 04 Sep 2016, 07:15

When is the last time the system was charged?
Has the system been checked for leaks?

I don't understand your description..."The AC pump is new and fully was Volvo Dealer serviced..it frozen in the middle of all of this". What is that supposed to mean? It's not a coherent sentence.

MLS1965 · Post by **MLS1965** » 04 Sep 2016, 07:24

The AC compressor is new and was dealer replaced last year. The system is fully serviced and has no leaks. If that was the cause of my issue it would just blow warm air all the time...that's not the case. Every now and then it blows cold. My question is it looks to be tied to a temp sensor..etc. something that fails intermittently.

Post by **alschnertz** » 05 Sep 2016, 07:14

Is the AC compressor cycling on and off consistent with the warm air / cool air? (Just trying to eliminate a blend door issue)

I had issues with a fan transistor, but that only had to do with fan speed, not temp.

Sometimes solder joints will crack on the pc boards of sensors, relays, speedometers etc.. I wonder if you can pull the ECC unit and check the internal solder connections with a magnifying glass. I've never had mine apart.

FWIW, I've re-soldered an ABS sensor and a few relays with success on my 854T.

MLS1965 · Post by **MLS1965** » 07 Sep 2016, 14:58

The compressor was not cycling off/on and it was blowing warm air. The car ran for a good :10 minutes....nothing. Just the radiator fan cycling. I'm actually a commercial aircraft mechanic for 20 years so I understand a little of how things work and talk to each other. I read a thread on another page and it talked about a relay on the blending door that also works as a temp sensor..? Did I read that right. My guess would be it reads what temperature you have dialed into the ECC and regulates to door accordingly. Correct..?

MLS1965 · Post by **MLS1965** » 13 Sep 2016, 17:02

So, if it is a blend door issue..? Any good advice on how to change it...? Video on You Tube..? It blew cold today on the ride home, but who knows what tomorrow will bring. I've priced the part on line and at $70 it's worth a shot

Post by **alschnertz** » 14 Sep 2016, 14:56

So if the "compressor was not cycling off/on and it was blowing warm air" I'm not really surprised.
Given that, I don't think it's a blend door.

How do you know there are no leaks now? I mean, how do you know it hasn't developed any leaks since it was serviced?

MLS1965 · Post by **MLS1965** » 15 Sep 2016, 15:03

It was doing this before the compressor went out last year. To me if it had a leak or the pressure was low it would always blow warm air, plus looking at the sight gauge I don't see any foam. It's intermittent. Yesterday it worked, today it did not. Often when I get out of work and start my car it blows cold for a few minutes, then goes warm. It's frustrating to say the least. On the plus side, it's cooling off in middle Tennessee. It stinks, because except for this issue the car is great. No other issues, no rattles, gets great gas mileage ...31 MPG last fill up. The only issue I have is when I bought it used and did the Carfax it came back clean, but now it's clear it's been in some type off front end accident. Paint is peeling on the hood and fenders and if you look close you can see a tape line. Bummer because it's a sharp looking car. Myai Gold, Cyborg interior Option, all the options other then the trip computer..16" tires..

grga1 · Post by **grga1** » 26 Sep 2016, 08:54

I solved some of the weird problems I had with the climate control by disconnecting and spraying the connectors at the back of the unit with electrical grade lubricant. At the same time I cleaned the temperature sensor in the climate control module and fixed the non-working ambient temperature sensor (the one on the front bumper; don't think it is used by the climate control but who knows).

Having said so, I now have a new problem - the ac turns on each time I start the engine. Is there any way to reset the ccm without disconnecting the battery or pulling it out? Like some combination of buttons pressed?