Fuel pump relay: Notes

Fig 1: Communication Diagram - Fuel Pump Relay

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Fig 2: Circuit Diagram - Fuel Pump Relay

Courtesy of SAAB-SCANIA OF AMERICA, INC.

The fuel pump relay is located in the relay holder under the dashboard near the steering wheel. The relay feeds the fuel pump and the oxygen sensor preheating.

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.