Circuit/System Description

Battery voltage (B+) is supplied directly to the reverse lockout solenoid. The engine control module (ECM) controls the reverses lockout solenoid by grounding the control circuit via an internal switch called a low side driver. The low side driver has a fault line which monitors the control circuit. When the ECM commands the reverse lockout solenoid ON, the voltage on the control circuit should be low, near 0 volts. When the ECM commands the control circuit to the reverse lockout solenoid OFF, the voltage should be high, near battery voltage.