SAAB WIS ONLINE

A/C relay

A/C relay





When the A/C compressor is activated from the ACC or MCC and all other condition have been fulfilled, DICE will send bus information "A/C ON". The value is used by Trionic T7.

The control module then calculates the impending torque requirement of the compressor based on the A/C pressure and subsequently requests a corresponding increase in the air mass/combustion. After a short delay, the control module will ground pin 4, which is connected to the A/C relay.

The control module activates the relay only after the engine has started.



Diagnostics


If there is an open circuit or short circuit to ground, diagnostic trouble code P1656 will be generated.

If there is a short circuit to B+, diagnostic trouble code P1657 will be generated.

Note

The A/C request from DICE can be read with the diagnostic tool.