[billy2008]

Searched crazy, but can’t seem to find anything beyond the one line description for this error code. Anybody have experience successfully resolving this acc error ?. Is it responsible for no cold air or are these two issues unrelated? Thanks for any leads.

 

[Doug]

I guess you know what the code means. First question I’d ask is does your car actually have the valve? My 2004 never did. Second, is your ACC panel the original for that car? They’re programmed according to the car’s original spec so if you have an ACC panel it might throw faulty codes.

I can’t see that fault being responsible for no cold air. The valve is designed to cut off the hot coolant supply to the heater matrix, to enable more air con cooling. If the valve is not working, the matrix gets hot coolant but it doesn’t stop the air con working.

Doug

 

[billy2008]

Thanks !
It’s the original ac unit. so if error 18 isn’t impacting cooling , any thoughts on what might be and how to troubleshoot that?

 

[billy2008]

Could it be the a/c compressor?

 

[TrollhattenMercedes]

Could be a plugged A/C expansion valve. When you park the car is there a lot of water on the ground under the passenger side after it sits a while? This would mean that the expansion valve is plugged and icing over during the drive then that ice will melt once the car is sitting.

 

[billy2008]

Is it accurate that the compressor won’t engage if the system is low on r134a?

 

[bob3000]

Is it accurate that the compressor won’t engage if the system is low on r134a?

Yes, the system won't function unless the pressures are correct.
.

 

[billy2008]

How do I find the expansion valve?
I blew out the drain line w compressed air and I also checked the low pressure side ac line — it was “empty”. I put some r134a in to just get into the green pressure indicator. Compressor clutch engages now / spins but still no cold air!
Also now there is a “honking” type sound / noise coming from what seems like the high pressure line or radiator at the front of the engine bay. More thoughts?

 

[bob3000]

More thoughts?

The expansion valve is on the firewall, passenger side.

More thoughts...take it to a shop that services Air Conditioning before you damage something that is worth more then the car is.

 

[billy2008]

Oh bob.