P1004 Subaru Short Runner Valve Control Performance

Possible causes

– Faulty short runner valve assembly
– Short runner valve harness is open or shorted
– Short runner valve circuit poor electrical connection
– Faulty Powertrain Control Module (PCM)

What about the obd code?

The P1004 Subaru code is detected when the value is determined to be out of the calibrated range in either the de-energized, greater than 85% duty cycle or less than 75% duty cycle, or energized, greater than 55% duty cycle or less than 35% duty cycle, state for more than a calibrated amount of time, this DTC will set.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P1004 Subaru Description

The Short Runner Valve (SRV) system is used to improve engine performance. The SRV system allows the intake charge air to bypass the long intake manifold runners between the intake manifold plenum and the intake manifold interface to the cylinder heads by providing a shorter runner directly between the plenum and the cylinder head interface The SRV position is controlled by a pneumatic/spring actuator and electronic solenoid valve. The Powertrain Control Module (PCM) compares the circuit feedback to calibrated closed range when the circuit is deenergized or to a calibrated open range when the circuit is energized.