P205B

P205B-(DIESEL EXHAUST FLUID) REDUCTANT TANK TEMPERATURE SENSOR CIRCUIT RANGE/PERFORMANCE




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 in 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 in three consecutive key cycles.

- When Monitored:
This monitor runs continuously when Diesel Exhaust Fluid Tank heating is commanded.

- Set Condition:
The DEF Dosing Control Unit does not detect a corresponding temperature increase by the DEF Tank Temperature Sensor after the Diesel Exhaust Fluid Tank heating is commanded on.





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

1. CHECK THE ENGINE COOLANT LEVEL

NOTE: If there are DTCs present for the DEF Tank Temperature Sensor or DEF Engine Coolant Control Valve, perform those diagnostic procedures before continuing with this test procedure.

1. Turn the ignition off.
2. Verify the engine coolant level.

Is the engine coolant level above the minimum?

Yes

- Go To 2

No

- Fill the engine coolant to the proper level.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

2. CHECK FOR BLOCKED OR RESTRICTED ENGINE COOLANT LINES/HOSES
1. Visually inspect the engine coolant supply and return lines for signs of a restriction of leaks.

Were any restrictions or leaks found?

Yes

- Repair or replace the engine coolant lines.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 3

3. CHECK FOR BLOCKED OR RESTRICTED DIESEL EXHAUST FLUID TANK HEATER
1. Remove the coolant lines at the DEF Tank Heater Coil.
2. Blow regulated low pressure shop air through the DEF Tank Heater Coil.

Were any restrictions found?

Yes

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

No

- Replace the DEF Engine Coolant Control Valve. Diesel Exhaust Fluid Engine Coolant Control Valve - Removal.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.