S80 AWD V8-4.4L VIN 85 B8444S (2008)
The function of the starter motor relay is to supply power to the starter motor. See also: Function, B8444S See: Computers and Control
Systems/Description and Operation/Engine Control Module (ECM)/Function
The starter motor relay is in the relay/fusebox in the engine compartment.
Engine cooling fan (FC) / engine cooling fan (FC) control module
Note! The engine cooling fan may have a post-run of up to approx. 6 minutes after the engine has been turned off. The time for the fan's
post-run depends on engine temperature, temperature in the engine compartment and pressure level in the A/C-system.
Warning! Be careful since the engine cooling fan may have a post-run after the engine has been turned off.
The engine cooling fan (FC) consists of two fans and two control modules. The control modules are controlled by the same signal from the engine
control module (ECM).
Hint: Due to there being various engine cooling fan suppliers, there are engine cooling fan versions consisting of two fans and one control module.
The engine cooling fan (FC) has two functions. One is to cool the engine compartment, the other is to cool the condenser when the air conditioning (A/C)
compressor is working.
The engine control module (ECM) transmits a pulse width modulated (PWM) signal to the engine cooling fan (FC) control modules. The control
modules then activate the fans at different speeds. The speed is determined by the engine control module (ECM), depending on the coolant temperature
and the vehicle speed.
The temperature conditions for engagement of the different engine cooling fan (FC) stages may vary slightly, depending on the engine variant and the
equipment level. The temperature conditions apply when:
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the A/C is off
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no faults are detected by the engine control module (ECM).
The engine cooling fan (FC) is located behind the radiator and its control module is grounded and powered with battery voltage via a fuse.
There are diagnostics for the engine cooling fan (FC). The engine cooling fan (FC) transmits a diagnostic signal to the engine control module (ECM).
Fuel pump
