Faulty Reverse Inhibit Solenoid
Reverse Inhibit Solenoid harness is open or shorted
Reverse Inhibit Solenoid circuit poor electrical connection
Engine Light ON (or Service Engine Soon Warning Light)
An ignition voltage is supplied to the Reverse Inhibit solenoid. The Powertrain Control Module (PCM) controls the solenoid by grounding the control circuit via an internal switch called a driver. The driver supplies the ground for the component being controlled. Each driver has a fault line which the PCM monitors. When the PCM commands a component ON, the voltage of the control circuit should be low (near 0 volts). When the PCM commands the control circuit to a component OFF, the voltage potential of the circuit should be high (near battery voltage). If the fault detection circuit senses a voltage other than what is expected, the fault line status changes causing the P0801 code to set.