The engine's intake manifold tuning valve isn't responding properly to the computer's commands, like a dimmer switch that won't adjust the light. This prevents the engine from optimizing airflow for different driving conditions.

The ECM monitors the control circuit voltage and solenoid resistance of the intake manifold tuning valve, expecting specific electrical signals when opening and closing. It detects faults when circuit voltage is out of range, resistance is abnormal, or the valve fails to respond within expected timing thresholds.

Voltage & Parameter Thresholds