TITAN XD DIESEL DEF DOSING UNIT OVERRIDE TEST
REASON FOR THE TEST
Why run a Diesel Exhaust Fluid (DEF) Dosing Unit Override test?
- To check the operation of the DEF dosing valve after maintenance or repairs
- To check for proper operation as a diagnostic step
WHAT THE TEST DOES
The test consists of energizing the DEF pump and dosing valves to check the:
- spray pattern of the dosing valve and
- the volume of DEF delivered in a period of time.
NOTE: DEF may be referred to as “Reductant.”
DEF DOSING SYNOPSIS
When the DEF controller commands the DEF dosing unit to start its priming process, the DEF dosing unit:
- draws DEF from the DEF tank,
- pressurizes the DEF, and then filters the DEF and delivers it to the DEF dosing valve.
The DEF dosing valve opens and closes to remove excess air from the system. After the system builds pressure and removes most of the air bubbles from the lines, the DEF dosing system is ready to inject DEF into the exhaust.
To reduce the risk of personal injury, do not get Diesel Exhaust Fluid (DEF) in your eyes as it contains urea. In case of contact, immediately flush eyes with large amounts of water for a minimum of 15 minutes. Do not swallow. In the event DEF is ingested, contact a physician immediately. Reference the Safety Data Sheet (SDS) for additional information.
- Care should be taken when handling and/or disconnecting the DEF line from the DEF dosing valve. The intake connection of the DEF dosing valve is plastic and can be easily damaged.
- Do not connect a 12V or 24V supply to the DEF dosing valve as this will cause permanent damage.
INITIAL CHECK
Perform an initial visual check:
- Check for damage, kinks, or obvious leaks in the DEF line and connections between the DEF dosing unit and the DEF dosing valve.
- Check for an adequate amount of DEF in the DEF tank.
- Check the concentration and quality of the DEF.
CHECK CONCENTRATION AND QUALITY OF DEF
The concentration and quality are monitored by a DEF quality sensor mounted on the side of the DEF tank. This sensor detects the urea concentration in the DEF to confirm it is acceptable for effective dosing (approximately 32.5% urea).
- If the DEF quality sensor detects an incorrect DEF concentration:
- The DEF warning lamp in the combination meter will illuminate.
- The MIL may also illuminate.
- If the DEF tank is filled with anything other than DEF or has diluted DEF:
- The aftertreatment system will not operate correctly.
- A DTC will be set and engine power reductions will follow.
If you want to double check the accuracy of the quality sensor, manually check the DEF.
To do this, use Special Tool J-54466 refractometer to measure the concentration. Replace the DEF if the concentration is not within 32.5 ± 1.5%. If the concentration is not within the limits, replace the DEF. If you do not have Special Tool J-54466 and you suspect the DEF concentration may be out of range, replace the DEF with known good DEF.
PREPARE THE TEST
NOTE:
- Prior to performing this test, check and troubleshoot any DTCs, unless you have been directed to perform this test by DTC diagnostics.
- Low battery voltage can cause the dosing volume to be low. Check the batteries for proper condition before running this test.
1. Make sure the ignition is OFF.
2. Remove the DEF dosing valve.
- Refer to the Electronic Service Manual (ESM), section EX - Exhaust, for removal information.
3. Connect the electrical and DEF lines to the dosing valve.
4. Place the DEF dosing valve into a clean container.
DO NOT submerge the DEF dosing valve in solvent, water, or DEF. Damage to the DEF dosing valve will result.
NOTE:
It is usually easier to capture the DEF in a clean large container and then transfer it to the measuring container for the final measurement.
- Obtain a clear plastic container (large enough to hold the DEF dosing valve).
- During the test, the dosing valve will be in the container, and dispense 85-115 ml (2.9-3.9 oz) of DEF.
- Also obtain a graduated beaker, or equivalent.
- A measuring cup that is marked in milliliters (ml) or ounces (oz) can also be used.
- Cummins Part Number for the graduated beaker is 4919139.
- The measuring device must be capable of measuring between 0 ml (0.0 oz) and 500 ml (17.0 oz) in 5 ml (1/4 oz) increments.
- DO NOT pour DEF from the collection container back into the DEF tank. Dispose of the DEF in accordance with local environmental regulations.
PREFORM THE TEST
NOTE:
- When the test is started, the dosing system will first prime. While priming, the DEF dosing valve will open intermittently to purge air from the system. In doing so, some DEF will be sprayed from the tip. This is a normal.
- When the flow test begins, briefly monitor the spray pattern of the DEF exiting the DEF dosing valve. Check for the following:
- Signs of larger drops and/or dripping DEF from the tip.
- Spray pattern that is not symmetrical (sprays more to one side).
1. Turn the ignition ON (engine OFF).
2. Select “DEF Dosing Unit Override Test” in “Active Test” mode of “ENGINE” using CONSULT-III plus.
3. Touch “Start”.
4. Follow the instructions on CONSULT- III plus screen.
NOTE:
- CONSULT-III plus will start the test and will inject the DEF for 6 minutes.
- CONSULT-III plus will automatically disable the injector at the end of the test.
5. Perform the test three times. The amount of DEF measured for each test should be within 85-115 ml (2.9-3.9 oz).
6. If the amount of DEF is not within specification:
- Check that the DEF filter is not plugged.
- Check for leaks, kinks, or damage in the DEF lines.
- If a dosing valve requires replacement, it may have been plugged by debris. Inspect the DEF dosing unit filter for signs of contamination and debris prior to installing the new DEF dosing valve.
7. Disconnect the electrical and DEF lines from the dosing valve.
FINISHING STEPS
1. Install the DEF dosing valve.
- Refer to the ESM, section EX - Exhaust, for installation information.
2. Check for leaks.
