P1464

DTC P1464 Main Relay Performance

Circuit Description
The DEF control module internal main relay is energized to feed the battery voltage to the DEF control module when the DEF control module receives an ignition voltage switch ON signal. When the ignition switch is OFF, the main relay is deenergized after a certain length of time passed. If the DEF control module detects that the main relay command state and the control module ON/ OFF state are out of correlation, this DTC will set.

Condition for Running the DTC

Relay Stuck ON Error
- The ignition switch is OFF.

Control Module Shutdown Error
- The battery voltage is between 10 to 16 volts.
- The ignition switch is ON.

Condition for Setting the DTC

Relay Stuck ON Error
- The DEF control module detects that the main relay does not turn OFF when the relay is commanded OFF.

Control Module Shutdown Error
- The DEF control module detects a shutdown condition when the main relay is commanded ON.

Action Taken When the DTC Sets

Relay Stuck ON Error
- The DEF control module requests the ECM to illuminate the SVS. Refer to DTC Type Definitions for Action Taken When the DTC Sets - Type C. Diagnostic Trouble Code (DTC) Type Definitions
- The DEF control module and the ECM apply defaulted warning actions. Default Action and Fail-Safe List

Control Module Shutdown Error
- Refer to DTC Type Definitions for Action Taken When the DTC Sets - Type D. Diagnostic Trouble Code (DTC) Type Definitions

Conditions for Clearing the DTC

Relay Stuck ON Error
- Refer to DTC Type Definitions for Conditions for Clearing the DTC - Type C. Diagnostic Trouble Code (DTC) Type Definitions

Control Module Shutdown Error
- Refer to DTC Type Definitions for Conditions for Clearing the DTC - Type D. Diagnostic Trouble Code (DTC) Type Definitions

Diagnostic Aids
- If an intermittent condition is suspected, Intermittent Conditions

Test Description
The number below refers to the step number on the Circuit/ System Testing.
3. If DTC P1463 is not set in the ECM, the DEF control module internal main relay is stuck ON. Replace the DEF control module.

Circuit / System Testing DTC P1464