Description and Diagnostic Chart

SYSTEM: Turbo Control Circuit

WIRING DIAGRAM





CIRCUIT DESCRIPTION



This turbocharger system has 3 control valves (Exhaust Bypass Valve, Exhaust Gas Control Valve, Intake Air Control Valve). Each valve is controlled by a vacuum switching valve (VSV) based on signals from the ECM.
1. Exhaust Bypass Valve
This valve controls the opening or closing of the exhaust bypass passage to ensure a smooth transition from 1 turbo operation to 2 turbo operation.
2. Exhaust Gas Control Valve
This valve controls the opening or closing of the No. 2 exhaust passage in order to operate No. 2 turbocharger.
3. Intake Air Control Valve
This valve controls the opening or closing of the No. 2 intake air passage in order to pass the charged air from No. 2 turbocharger.

DIAGNOSTIC CHART
1. CHECK OPERATION OF VSV FOR EXHAUST BYPASS VALVE.
^ If OK go to step 2.
^ If not OK replace VSV.
2. CHECK OPERATION OF VSV FOR EXHAUST GAS CONTROL VALVE.
^ If OK go to step 3.
^ If not OK replace VSV.
3. CHECK OPERATION OF VSV FOR INTAKE AIR CONTROL VALVE.
^ If OK go to step 4.
^ If not OK replace VSV.
4. CHECK VOLTAGE BETWEEN TERMINALS VSV1, VSV2, VSV3 OF ECM AND BODY GROUND.
^ If OK check actuator. (for Exhaust bypass valve, Exhaust gas control valve, Intake air control valve)
^ If not OK go to step 5.
5. CHECK FOR OPEN AND SHORT IN VSV CIRCUIT.
^ If OK check and replace ECM.
^ If not OK repair or replace harness or connector.