Operation CHARM: Car repair manuals for everyone.

Description of Activations






Description of activations

Maximum blower fan relay




Activate the blower fan relay. The blower fan must run at maximum speed.
The function is activated until it is cancelled.

Request for rear defrosting

Note! Only if the car has a heated rear windshield and door mirrors.

Activate the relay for the heated windshield and door mirrors.
The function is activated until it is cancelled.

A/C LED

Note! Only if the car has air conditioning (A/C) (MCC, ECC).

Activates the LEDs in the A/C switch on the climate control module.
The function is activated until it is cancelled.

Recirculation LED
Activates the LED in the recirculation switch on the climate control module.
The function is activated until it is cancelled.

Defroster LED

Note! Only if the car has a heated rear windshield and door mirrors.

Activates the LED in the defroster switch on the climate control module.
The function is activated until it is cancelled.

LED for the left seat heater

Note! Only if the car is equipped with seat heaters.

Activates the LEDs in the left seat heater switch on the climate control module.
The function is activated until it is cancelled.

LED for the right seat heater

Note! Only if the car is equipped with seat heaters.

Activates the LEDs in the right seat heater switch on the climate control module.
The function is activated until it is cancelled.

A/C request

Note! Only if the car has air conditioning (A/C) (MCC, ECC).

Request for A/C to the relevant engine control module (ECM).
The engine control module (ECM) controls the engagement of the compressor clutch using the air conditioning (A/C) relay. The engine control module (ECM) controls the engagement of the condenser fan clutch using the air conditioning fan relay.

Note! See the inside of the cover for the integrated relay/fusebox in the engine compartment for the position of the relays.

Note! For the air conditioning (A/C) to engage, the engine must be running, the D+ signal must be active, the blower fan switch must not be in position 0 and the conditions for A/C engagement must be met.