Diagnosis Procedure

WARNING: This page is about a different car, the 2018 Nissan Titan XD. However, it is still accessible from the selected car via links, so may be relevant.

CHECK DTC PRIORITY
1. Turn ignition switch ON.
2. Connect CONSULT and check for "ENGINE" diagnostic trouble codes.
3. Check for DTC P1C56-00 being current on the CONSULT screen.
Is applicable DTC detected?

YES

GO TO 2 .

NO

Refer to Intermittent Incident .
CHECK DTC PRIORITY
Check for DTCS U029E-00, P220B-00, P229E-00 or P22A7-00 being current on the CONSULT screen.

Is applicable DTC detected?

YES

Refer to DTC Index .

NO

GO TO 3 .
CHECK DTC PRIORITY
Check for DTCS U029D-00, U059E-00, P1C55-00, P2201-00, P2202-00, P2209-00 or P220A-00 being current on the CONSULT screen.

Is applicable DTC detected?

YES

Refer to DTC Index .

NO

GO TO 4 .
CHECK INSTALLATION OF AFTERTREATMENT OUTLET NOX SENSOR
1. Turn ignition switch OFF.
2. Inspect aftertreatment outlet NOx sensor for proper installations.
Is the inspection result normal

YES

GO TO 5 .

NO

Correct installation of the outlet NOx sensor. Refer to Removal and Installation .
CHECK DECOMPOSITION TUBE FOR CRYSTALLIZATION
1. Turn ignition switch OFF.
2. Disconnect the aftertreatment DEF decomposition tube.
3. Inspect the decomposition tube for crystallization.
Is the inspection result normal

YES

GO TO 6 .

NO

Remove crystallization buildup.
CHECK EXHAUST SYSTEM FOR LEAKS
Inspect the exhaust system for leaks:
- Leaks should be easily noted by traces of soot.
- If necessary, run the engine at idle speed to help detect any leaks.
Are any leaks detected?

YES

Repair or replace leaking exhaust system component.

NO

Replace the outlet NOx sensor. Refer to Removal and Installation .