DEF System Leak Test: Inspection
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.
- While the test is running, inspect all DEF lines, fittings, and connections for external leaks. Refer to Removal and Installation (DEF dosing valve) or Removal and Installation (DEF tank).
Repair and replace any leaking component(s).
NOTE: If the system is unable to prime due to leaks, it will be necessary to turn the keyswitch OFF in order to stop the dosing unit. The dosing unit cannotbe stopped using CONSULT. - Upon completion of inspecting the lines, fittings, and connections for leaks, press the stop button in CONSULT. The dosing unit will then purge the system of DEF. An audible purging noise will be noticeable.NOTE:
- If the test is not stopped using CONSULT, it will continue to pump for 20 minutes and then automatically purge the system of DEF.
- If the system is able to successfully prime, a pop-up message will appear in CONSULT to notify the technician.
- If the system cannot build pressure, it will attempt to prime multiple times before flagging a fault code.
If any fault codes occur while running this test, reference the appropriate DTC Diagnosis Procedure.
NOTE:- If the system fails to prime, a key cycle will be required before attempting to run the DEF System Leak Test again.
- The Aftertreatment DEF System Leak Test cannot be attempted twice consecutively. A key cycle will be required before attempting to run the Aftertreatment DEF System Leak Test again after two attempts.
- During the test, a small quantity of DEF is sprayed into the decomposition tube. After completion of the test, it is necessary to run the engine at high idle for 5 minutes in order to prevent DEF deposits from forming in the decomposition tube.
- Check for P-codes.