Electrical Pump

The pump is located under the left-hand front wing and is connected via a non-return valve to the brake servo. The pump is supplied with current via a relay in the relay box in the engine bay. The relay is controlled from pin 52 of the engine control module, which is grounded to start the pump. The connection cable has three diodes connected in series to ensure that the pump is fed with the correct voltage, and that the correct pump speed is attained.
The conditions for control module activation of the output to start the pump are as follows:
^ The engine has started
^ The pressure in the intake manifold exceeds 58 kPa
^ The accelerator is released
^ The brake pedal is depressed When the above conditions are fulfilled the pump will be activated for 3 seconds.
For a description of engine control module operation, refer to Powertrain Management.

Diagnosis
The relay can be activated by means of the diagnostics instrument.