GF42.60-P-5500-02A Brake Booster Vacuum Pump Control Unit, Function

GF42.60-P-5500-02A Brake booster vacuum pump control unit, function
- with CODE (423a) 5-speed automatic transmission (new-generation)

Component Identification:

The vacuum pump control unit is divided up functionally as follows:
^ Signal conditioning
^ Function logic component
^ Safety circuit

Signal conditioning
The following input signals are processed by the function logic section:
- Vacuum sensor (internal)
- Stop lamp switch signal (on gasoline engine via CAN)

Function-logic section
The conditioned input signals are processed in the logic section and are decisive for the actuation of the electrical vacuum pump.

When the brake is pressed the stop lamp switch signal is passed on to the brake booster vacuum pump control unit (on the gasoline engine by the CAN data bus via the ESP control unit). The brake booster vacuum pump is actuated when the vacuum measured by an internal sensor is < 500 mbar.

The brake booster vacuum pump is switched off after a run-on time of 1 second when the measured vacuum is > 700 mbar.

If the pump does not reach the cutoff pressure after a runtime of approx 70 seconds (e.g. due to a leak in the system), it is switched off. As a limp-home function the pump is only switched on if the brake is actuated.

Safety circuit
The safety circuit detects faulty signals from sensors, faults in the control unit and in the electric line system. If a fault is detected, a fault code is stored in the control unit

The safety circuit also constantly monitors the battery voltage. If the voltage falls below 7 V or exceeds 18 V, the system is switched off until the voltage returns to the specified range.