Variable Induction System: Testing and Inspection

Intake Manifold Change-Over

The intake manifold change over function switches over from the long intake tract to the short intake tract at about 4200 rpm.

Intake Manifold Change-over Function, Checking

This check should only be carried out if the engine is losing power.







- Remove front engine cover (arrows).
- Start engine and increase engine speed to over 4200 rpm.







- Operating rods of actuator for intake manifold (arrow) must move

If the change-over is not taking place, perform the following checks:
- Check intake manifold change-over valve -N156- (perform output DTM, if necessary, check valve and activation). Output Diagnostic Test Mode (DTM) (Function 03) Testing and Inspection
- Check vacuum system for leaks. Vacuum System, Checking For Leaks
- Check that vacuum hoses are properly connected and free of leaks and obstructions.
- Check that change-over mechanism operates freely (move push rod by hand).