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Detailed description, radiator fan

Detailed description, radiator fan

Radiator fan logic

The car is equipped with a radiator fan located behind the radiator. The radiator fan can be operated in three different stages, depending on the engine temperature and AC pressure.

The fans are controlled by ECM through the following input signals:


• Coolant temperature

• A/C pressure



Radiator fan relay box (706) is supplied with +30 from UEC to pin 5 and is grounded to G30A from pin 2.

From ECM come 3 cables via the engine bay electrical centre to the relay box. These cables are connected to pins 1, 4 and 7 on the relay box. Depending on the connection being grounded and the combination in which they are grounded, three different speed stages can be obtained for the radiator fans.

The radiator fans will start in the following cases when the ignition is ON:



1. Temperature logic:

Stage one for the radiator fans occurs when the coolant temperature reaches XXX C and ceases when the temperature drops to XX C.

Stage 2 for the radiator fans occurs when the coolant temperature reaches XXX C and returns to stage 1 at XXX C.

Stage 3 for the radiator fans occurs when the coolant temperature reaches XXX C and returns to stage 2 at XXX C.

2. A/C pressure logic

Stage 1 on the radiator fans starts at an A/C pressure over 1300 kPa and ceases at a pressure below 1000 kPa.

Stage 2 on the radiator fans starts at an A/C pressure over 1800 kPa and returns to stage 1 at a pressure of 1500 kPa.

Stage 3 on the radiator fans starts at an A/C pressure over 2500 kPa and returns to stage 2 at a pressure of 2200 kPa.