Diagnosis Procedure

1. Turn ignition switch ON.
2. Connect CONSULT and check for existing ENGINE diagnostic trouble codes.
3. Check for DTC P20EE-00 current on the CONSULT screen.

Is applicable DTC current?

YES

GO TO 2 .

NO

Refer to Intermittent Incident .

Using CONSULT, check ENGINE diagnostic trouble codes for the following higher priority DTCs:

• U029D-00
• U029E
• U059E
• U059F-00
• P1C55
• P2201-00
• P2202-00
• P2209-00
• P220A
• P220B-00
• P229E
• P229F-00
• P22A7

Are there any of the above DTCs current?

YES

Go to the appropriate diagnosis procedure. Refer to DTC Index .

NO

GO TO 3 .

Using CONSULT check ENGINE diagnostic trouble codes for DTCs related to SCR temperature sensor.

Are there any current DTCs related to SCR temperature sensor?

YES

Go to the appropriate diagnosis procedure. Refer to DTC Index .

NO

GO TO 4 .

Using CONSULT check ENGINE diagnostic trouble codes for DTCs related to DEF dosing system.

Are there any current DTCs related to DEF dosing system?

YES

Go to the appropriate diagnosis procedure. Refer to DTC Index .

NO

GO TO 5 .

1. Start the engine.
2. Check the exhaust for leaks.
3. Inspect the entire exhaust system between the turbocharger outlet and the SCR outlet. Inspect for loose connections, leaking connections, and broken exhaust system components.

Exhaust system leaks found?

YES

Repair or replace the damaged exhaust system component.

NO

GO TO 6 .

1. Turn ignition switch OFF.
2. Inspect all components of the after treatment DEF dosing system for signs of external leaks, including:
   • Tank connectors.
   • Dosing unit and dosing unit connectors.
   • Lines.
   • Dosing valve.
   • DEF will form white deposits around leaky fittings.

DEF leaks detected in the system?

YES

Repair the source of the external leak.

NO

GO TO 7 .

1. Inspect the DEF in the tank for signs of debris or contamination.
2. Using a refractometer [SST: J-54466] measure the concentration of the DEF in the tank.

Is DEF concentration within 32.5 A± 1.5 %?

YES

GO TO 8 .

NO

Drain the DEF tank, rinse with water, and refill with pure DEF.

1. Connect all components and harness connectors.
2. Remove the after treatment DEF dosing valve from the decomposition tube.
3. Place the DEF dosing valve in a measuring container having greater than a 1.5 liter [50 oz] capacity.
4. Turn ignition switch ON.
5. Using CONSULT, access ENGINE and select "DEF Dosing Unit Override Test" active test.

Did the DEF dosing unit operate according to specifications?

YES

GO TO 9 .

NO

Replace the DEF supply pump assembly. Refer to Exploded View .

Using CONSULT, access ENGINE and select DEF Dosing Unit Leak Test active test.

DEF leaking from the DEF dosing valve during the system leak test?

YES

A leaking after treatment DEF dosing valve has been detected. Replace the after treatment DEF dosing valve.

NO

GO TO 10 .

1. Turn ignition switch OFF (do not operate the engine).
2. Inspect the decomposition tube for deposits.
3. Remove the decomposition tube from the vehicle.
4. Inspect for excessive DEF deposits.

Excessive DEF deposits found inside the decomposition tube?

YES

• Clean and install the decomposition tube.
• GO TO 11 .

NO

• A malfunctioning SCR catalyst has been detected. Replace the after treatment SCR catalyst. Refer to Removal and Installation .
• Replace the after treatment intake NOx sensor. Refer to Removal and Installation .
• Replace the after treatment outlet NOx sensor. Refer to Removal and Installation .
• GO TO 11 .

1. Using CONSULT, select ENGINE and erase DTCs.
2. Operate the engine within the "Conditions for Clearing the DTC".

Is P20EE-00 DTC current?

YES

Diagnosis procedure needs to be repeated. Refer to DTC Description .

NO

Repair complete.