Circuit Description

A supercharger by-pass valve (stepper motor) controls the amount of air by-passing supercharger. The ECM controls stepper motor to regulate amount of intake air to by-pass the supercharger depending on engine operating condition.

The ECM turns supercharger magnetic clutch relay off as a fail-safe function when intake air volume flow rate is too high. Code is set when intake air volume flow rate is too high or too low with supercharger clutch relay is on and engine speed is 2800 RPM or greater. Possible causes are:

• Supercharger magnetic clutch relay open or short circuit.
• Supercharger magnetic clutch relay.
• Supercharger magnetic clutch.
• Supercharger by-pass valve open or short circuit.
• Supercharger by-pass valve.
• ECM.
• Air intake hose.