P20A0

DTC P20A0 Diesel Exhaust Fluid (DEF) Reverting Valve Circuit Open

Circuit Description

The DEF reverting valve is internal to the DEF supply pump and it switches the DEF flow direction based on the command from the DEF control module. When the reverting valve is commanded OFF, a normal DEF flow is formed and the pressurized DEF from the pump is sent to the DEF injector via the pressure line. When the reverting valve is commanded ON at the pressure reduction control or after run control, a reverse DEF flow direction is formed and the pump returns the DEF to the tank. The reverting valve has a power supply circuit and a control circuit. The power supply circuit provides a battery voltage to the reverting valve from the control module internal high side driver circuit, and the reverting valve is energized through the control circuit by pulling the internal low side driver circuit to the ground when it is commanded ON. If the DEF control module detects an open circuit on the reverting valve control circuit, this DTC will set.

Condition for Running the DTC

- The battery voltage is between 10 to 16 volts.
- The ignition switch is ON.

Condition for Setting the DTC

- The DEF control module detects an open circuit on the reverting valve control circuit for 3 seconds.

Action Taken When the DTC Sets

- The DEF control module requests the ECM to illuminate the MIL. Refer to DTC Type Definitions for Action Taken When the DTC Sets - Type A.
- The DEF control module and the ECM apply defaulted warning actions. Refer to Default Action and Fail-Safe List.

Conditions for Clearing the DTC

- Refer to DTC Type Definitions for Conditions for Clearing the DTC - Type A or Type B.

Diagnostic Aids

- If an intermittent condition is suspected, refer to Intermittent Conditions in this section.

Circuit / System Testing DTC P20A0