What controls the AC compressor relay?
The relay in your car or light truck’s air conditioning system controls the compressor. By using a relay, the high-current electromagnetic compressor clutch can be controlled by a low-current switch.
Does the PCM control the AC compressor?
Yes, the PCM is what energizes the A/C Compressor, once it receives instructions to do so from other systems.
Can a bad PCM cause the AC not to work?
A bad PCM can cause the compressor to not kick on. It’s not a program issue, it’s a driver in the PCM that grounds the compressor relay. The pressure switch verification and the AC request signal are looked for by the PCM.
Does the ECM control the air conditioner?
An electronic control module is used to control the air conditioning compressor’s motor. When the information is processed, a signal is sent to the car’s electronic control unit that tells it how much power to send to the compressor. …
When did my Subaru Forester compressor give up?
My AC compressor decided to finally give up. I purchased the vehicle in October of 2018 with 78k at which time clutch made a whining noise when engaged and the AC was working fine. The other day it was warm enough that I thought to turn on the AC to no avail. It blew warm air and whats more the clutch was no longer engaging.
When did my Subaru Forester clutch stop working?
I purchased the vehicle in October of 2018 with 78k at which time clutch made a whining noise when engaged and the AC was working fine. The other day it was warm enough that I thought to turn on the AC to no avail. It blew warm air and whats more the clutch was no longer engaging.
Why does my Subaru Forester have no AC?
In troubleshooting I determined that the fuses and relay were fine. However, at the relay l could measure the 14.24V on one terminal and nothing on the other three terminals regardless if i turn on the AC or not. Swapping relays made no difference. At any rate I jumpered the coil to mimick the relay being engaged and the AC clutch engaged.
How does the PCM control the AC compressor relay?
Also whit the switches closed (i.e. pressure OK) the PCM controls the relay via pin 27, closing the relay contacts (thus engaging the A/C clutch) when command received as long as the engine is in the proper RPM range.