P203C

DTC P203C Diesel Exhaust Fluid (DEF) Level Sensor Circuit Low Voltage

Circuit Description

The DEF level sensor with DEF tank temperature sensor is installed to the DEF tank. The DEF level sensor consists of the float and the sensor tube. The float with a magnet is installed to the level sensor tube. In the sensor tube, there is a circuit board that the lead switches with different resistance are built. The DEF level is determined by a combined resistance value where the lead switch built on the circuit board is switched by a magnetism provided from the float installed to the sensor tube. The sensor has a signal circuit and a low reference circuit. When the DEF level is high, the sensor resistance is low and the DEF control module detects a low voltage on the signal circuit. When the DEF level decreases, the sensor resistance increases and the DEF control module detects a higher voltage on the signal circuit. The IP cluster receives the DEF level signal from the DEF control module via CAN communication bus. If the DEF control module detects an excessively low signal voltage, 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 that the DEF level sensor signal voltage is less than 0.2 volts for 4 seconds.

Action Taken When the DTC Sets

- The DEF control module requests the ECM to illuminate the SVS lamp. Refer to DTC Type Definitions for Action Taken When the DTC Sets - Type C.
- 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 C.

Diagnostic Aids

- If an intermittent condition is suspected, refer to Intermittent Conditions in this section.
- Use the Level Sensor Height vs. Resistance table to test the DEF level sensor at various height levels to evaluate the possibility of a skewed sensor.

The DEF Tank Level parameter on the scan tool indicates 3% if this DTC is present.

Test Description

The number below refers to the step number on the Circuit/ System Testing.
3. If the DEF level sensor signal circuit is normal, voltage level high DTC P203D will set.

Circuit / System Testing DTC P203C