Revolution Sensor & Fuel Pump Control
- Locate revolution sensor under left side of dash. Disconnect connector. Turn ignition on and ensure 12 volts are present on Black/White and Blue/Black wires.
- If not, check ignition switch and related circuits. If 12 volts present, turn ignition off. Using an ohmmeter, ensure Black wire has continuity to ground.
- Turn ignition on and jumper Blue wire to ground. Ensure the solenoid valve clicks. If not, check solenoid resistance, 12 volts present on Black/White wire and related circuits.
- Turn ignition off. Reconnect harness to revolution sensor. Start engine. If fuel pump does not operate, check for a tachometer signal (voltage pulses) on Yellow wire. If tachometer signal is present, replace revolution sensor. If no tachometer signal, check ignition switch, fuses, ignitor and related circuits.
- Start engine and warm to operating temperature. Using a DVOM, backprobe the Blue or Blue/Yellow wire at the revolution sensor. Ensure there is over 5 volts. If not, check solenoid and related circuits for open or short.
- Increase engine speed to over 3500 RPM. DVOM should now show 0-4.5 volts at Blue or Blue/Yellow wire. If not, replace revolution sensor.
Courtesy of SUBARU OF AMERICA, INC.