DTC P1569: Variable Tumble Control System Solenoid Valve Circuit, Low Input: Condition

DTC is set when PCM detects low voltage input from Variable Tumble Control System (VTCS) solenoid valve when VTCS solenoid valve is off. This is a continuous monitor. MIL is illuminated when PCM detects malfunction during 2 consecutive drive cycles. Possible causes are:

Open or Short circuit between VTCS solenoid valve and PCM.
Open circuit between VTCS solenoid valve and main relay.
VTCS solenoid valve malfunction.
PCM malfunction.