Symptoms

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

Possible Causes

- Swirl control valve position sensor circuit is open or shorted - Faulty swirl control valve position sensor - Swirl control valve circuit is open or shorted - Faulty swirl control valve

When Detected

The P1138 code is detected when the target opening angle of swirl control valve controlled by ECM and the input signal from swirl control valve position sensor is not in the normal rang.

Description

Swirl control valve consists of actuator and valve. The valve is installed in the intake manifold, and the actuator is connected to the rear end of the valve shaft. The swirl control valve uses a step motor which has four winding phases. It operates according to the output pulse signal of the ECM. Two windings are turned ON and OFF in sequence. Each time an ON pulse is issued, the valve opens or closes. When no change in the control position is needed, the ECM does not issue the pulse signal. A certain voltage signal is issued so that the valve remains at that particular opening.