A/C compressor not engaging

Laskoskisc · Post by **Laskoskisc** » 02 Apr 2016, 16:08

Car is salvaged - recovered stolen vehicle - so not under warranty. 2013 C30 Polestar with 31K miles.

A/C stopped working recently. Took to an independent mechanic to troubleshoot. He can see the AC signal go on/off. He can also trigger the ECM to turn the compressor on. So, believes CCM and ECM aren't communicating ... just not sure if issue is CCM sending or ECM receiving. Said movement of info on CAN too fast to tell. Now wants to begin replacing models, starting with CCM, and if that doesn't work, moving on to ECM. ~$1,500 a pop b/n parts and labor, so not liking the trial and error approach here.

My only other thought might be the WOT signal? Ideas?

Post by **JDS60R** » 02 Apr 2016, 16:25

I'm more concerned with if the compressor cycles when commanded as well as the pressures in the system. Your ccm can command on all day but if the pressure is low the compressor will not activate or cycle on then off.

mf70 · Post by **mf70** » 10 May 2016, 14:04

Does the compressor clutch engage when commanded? This is an issue with these cars. A simple shim kit often fixes it.

Post by **MadeInJapan** » 12 May 2016, 21:15

JDS60R wrote:I'm more concerned with if the compressor cycles when commanded as well as the pressures in the system. Your ccm can command on all day but if the pressure is low the compressor will not activate or cycle on then off.

Yes, it could be as simple as needing a good charge. Take the A/C cap off for charging under the hood and measure the pressure with the A/C engaged. If it's low, topping off is not that difficult to do- simple hose kit from pretty much any auto parts store.