P203C

P203C-(DIESEL EXHAUST FLUID) REDUCTANT LEVEL SENSOR CIRCUIT LOW




For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation

The Diesel Exhaust Fluid (DEF) Tank Level Sensor and Diesel Exhaust Fluid (DEF) Tank Temperature Sensor are a combination sensor used to measure the level and temperature of the fluid inside the DEF Tank. Though combined, the level sensor and the temperature sensor operate independent of each other. Both sensors operate as a two wire 5-Volt sensor. The DEF Tank Level Sensor is a 14 point magnetic reed switch sensor. The DEF Tank Temperature Sensor is a negative temperature coefficient sensor. The DEF Dosing Control Unit will illuminate the MIL lamp via the Powertrain Control Module (PCM) immediately after this diagnostic runs and fails. The DEF Dosing Control Unit will turn off the MIL lamp via the PCM immediately after the diagnostic runs and passes. The DEF system will continue to dose and the NOx monitor will continue to execute while the DTC is active.

- When Monitored:
With the ignition on.

- Set Condition:
The DEF Dosing Control Unit detects that the (K414) DEF Tank Level Sensor Signal circuit is below 0.25 of a Volt for one second.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC
1. Turn the ignition on for one minute, engine not running.
2. With the scan tool check for active DTCs.

Is the DTC active?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION - 6.7L. Intermittent Condition Test

2. CHECK THE DEF TANK LEVEL SENSOR
1. Ignition on, engine not running.
2. Disconnect the DEF Tank Level/Temperature Sensor harness connector.
3. With the scan tool check DTCs.
4. Monitor the scan tool for one minute.

Did DTC P203D set as active after disconnecting the sensor?

Yes

- Replace the DEF Tank Level/Temperature Sensor. Diesel Exhaust Fluid Level/Temperature Sensor - Removal.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 3

3. CHECK THE (K414) DEF TANK LEVEL SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND




1. Turn ignition off.
2. Disconnect the DEF Dosing Control Unit C1 harness connector.
3. Measure the resistance between ground and the (K414) DEF Tank Level Sensor Signal circuit at the DEF Tank Level/Temperature Sensor harness connector.

Is the resistance above 10k Ohms?

Yes

- Go To 4

No

- Repair the (K414) DEF Tank Level Sensor Signal circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

4. CHECK FOR THE (K414) DEF TANK LEVEL SENSOR SIGNAL CIRCUIT SHORTED TO THE (K420) DEF TANK LEVEL SENSOR RETURN CIRCUIT




1. Measure the resistance between the (K414) DEF Tank Level Sensor Signal circuit and the (K420) DEF Tank Level Sensor Return circuit at the DEF Tank Level/Temperature harness connector.

Is the resistance above 10k Ohms?

Yes

- Replace the DEF Dosing Control Unit. Diesel Exhaust Fluid Dosing Control Unit - Removal.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Repair the short between the (K414) DEF Tank Level Sensor Signal circuit and the (K420) DEF Tank Level Sensor Return circuit.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.