P209F

P209F-(DIESEL EXHAUST FLUID) REDUCTANT TANK HEATER CONTROL CIRCUIT PERFORMANCE




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

The Diesel Exhaust Fluid (DEF) Tank has an internal heating coil to help eliminate freezing of Diesel Exhaust Fluid. The DEF Dosing Control Unit monitors the temperature of the Diesel Exhaust Fluid inside the tank. When it is determined that the Diesel Exhaust Fluid needs to be heated, the DEF Dosing Control Unit opens the DEF Engine Coolant Valve which is located nest to the DEF Tank, and allows warm engine coolant to circulate through the heating coil inside the tank to warm the Diesel Exhaust Fluid in the tank. The DEF Dosing Control Unit will illuminate the MIL lamp via the Powertrain 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 for three consecutive key cycles.

- When Monitored:
This diagnostic runs a calibrated amount of time after Diesel Exhaust Fluid Tank heating is first commanded.

- Set Condition:
The DEF Tank heater has been on long enough for sufficient thawing of the Diesel Exhaust Fluid and the DEF system is still not able to prime.





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

1. OTHER DTCs
1. Turn the ignition on, engine not running.
2. With the scan tool, View DTCs.

Are any of the P202A, P202B, P202C, P205C, P205D, P205E DTCs Active?

Yes

- Perform the diagnostic procedures for the other active DTCs before proceeding with this test.

No

- Go To 2

2. 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 3

No

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

3. CHECK FOR RESTRICTED OR LEAKING ENGINE COOLANT LINES/HOSES
1. Visually inspect the engine coolant supply and return lines for signs of a restriction or 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 4

4. CHECK FOR 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.