Fuel Pump Relay: Notes

Fig 1: Diagnostic Communication For Fuel Pump Relay

Courtesy of SAAB-SCANIA OF AMERICA, INC.

The fuel pump relay is located in the relay holder under the dashboard by the steering wheel. The relay supplies the fuel pump and the oxygen sensor pre-heating.

The fuel pump relay is controlled from pin 50, which is grounded so that the relay will operate.

When the ignition switch is turned to "ON", the fuel pump relay operates for 1 second. This is to build up pressure before pre-injection, which takes place when the crankshaft begins to rotate.

Fig 2: Fuel Pump Relay Circuit Diagram

Courtesy of SAAB-SCANIA OF AMERICA, INC.