Multi-Ram System Diagnosis: Description

Multi-ram system uses variable air induction tuning to achieve maximum performance and efficiency over all engine operating ranges. System consists of a intake plenum switchover valve and a intake resonance switchover valve. Intake manifold contains the intake plenum switchover valve. Vacuum operated valve is a moveable divider which changes airflow in intake manifold.

Intake resonance switchover valve is located in air intake duct in front of engine. This moveable divider changes the tuning of air intake system. Vacuum to valves is controlled by a Engine Control Module (ECM) controlled solenoid valve. By opening and closing valves independently, in different combinations, 4 different airflow configurations can be created. Each configuration is optimized to a particular set of engine operating conditions.

If a malfunction is detected in either valve, a diagnostic trouble code will set. For testing procedures, see TESTS W/CODES article. For wiring schematics, see appropriate diagram in the WIRING DIAGRAMS article.