900 Turbo Convertible L4-1985cc 2.0L DOHC Turbo EFI (1994)
Fuel Pump Relay: Description and Operation
The fuel pump relay is located in the relay board under the facia at the steering wheel. The relay supplies the fuel pump and the oxygen sensor heater.
The fuel pump relay is controlled from pin 56 of the ECM which is grounded for the relay to operate.
If the engine has been started and the ignition has then switched off for more than 45 seconds, the fuel pump relay will operate for approx. 2 seconds
when the ignition is next switched on, to allow for preinjection. On the other hand, if the ignition has been switched on but the engine has not been
started, the ignition must be switched off for 15 minutes before further pre-injection takes place.
The fuel pump relay then operates as soon as the ECM receives pulses from the crankshaft position sensor.
