9-3 Viggen Convertible (9400) L4-2.3L Turbo (B235) HO (2001)
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Brake Fluid Pump: Description and Operation
ABS 5.4
Return pump
ABS 5.4 Return Pump
The return pump is integrated in the hydraulic unit and consists of a d.c. motor which drives a hydraulic pump.
The pump unit, which is only activated when an outlet valve is open, returns surplus brake fluid to the master cylinder.
The pressure in the return-fluid line is determined by the brake pressure in the master cylinder, which, in turn, is proportional to the pedal pressure.
The pump's capacity of approximately 250 bar is sufficient for all occurring braking conditions.
Each time the ignition is switched on and the road speed exceeds 6 km/h, the control module checks the operation of the return pump, activating it for
200 ms. If the brake-light switch is closed, the test will be done at a speed of 15 km/h.
The hydraulic pump and electric motor are an integral part of the valve block and cannot be replaced separately.
Diagnosis
In the event of a fault in the pump motor and/or wiring, diagnostic trouble code C2465 will be generated and the ABS function will be disabled at the
same time as the ABS lamp, brake fluid warning lamp and central warning lamp come on.
