Cummins ISX11.9 CM2250 – Service Manual 011-059   Aftertreatment Diesel Exhaust Fluid Dosing Valve

The aftertreatment diesel exhaust fluid (DEF) dosing valve (1) is used to spray diesel exhaust fluid into the exhaust flow prior to the intake of the selective catalytic reduction (SCR) catalyst (2). The aftertreatment DEF dosing valve is located on the decomposition tube (3), mounted on a flange with three capscrews.

NOTE: The same aftertreatment DEF dosing valve is used for 12-VDC and 24-VDC systems.

There are three primary connections at the aftertreatment DEF dosing valve:

1. A 2-pin electrical connection (4), which connects the aftertreatment DEF dosing valve to the aftertreatment DEF controller
2. A diesel exhaust fluid supply line (5), which connects the aftertreatment DEF dosing valve to the aftertreatment DEF dosing unit
3. Coolant supply and return connections (6), which connect the aftertreatment DEF dosing valve to the engine cooling system.

Use the following procedure for further information on the operation of the aftertreatment DEF dosing valve. Refer to Procedure 011-999 in Section F.  Use the following procedure for information on handling incorrect or contaminated diesel exhaust fluid. Refer to Procedure 011-056 in Section 11.

WARNING  During regeneration, the exhaust gas temperature could reach 800°C [1500°F], and the exhaust system surface temperature could exceed 700°C [1300°F], which is hot enough to ignite or melt common materials, and to burn people. The exhaust and exhaust components can remain hot after the vehicle has stopped moving. To avoid the risk of fire, property damage, burns or other serious personal injury, allow the exhaust system to cool before beginning this procedure or repair and make sure that no combustible materials are located where they are likely to come in contact with hot exhaust or exhaust components.

CAUTION  Do not use the flow test portion of INSITE™ electronic service tool Diesel Exhaust Fluid Doser Pump Override Test to check the system for leaks.  This will spray DEF into the exhaust system at too low of a temperature to evaporate, resulting in deposit formations in the exhaust system.

NOTE: DEF deposits may be left over from a previous DEF spill or repair. Check for leaks before replacing any components.

Inspect the area around the DEF line connection location, at the aftertreatment diesel exhaust fluid dosing valve.

Visually check for signs of leaks and/or white deposits. A DEF leak in this area may come from the following locations:

• The connection between the DEF line and the aftertreatment DEF dosing valve.

NOTE: Do not remove the DEF dosing valve (1) from the assembly (2).  It is not a serviceable part.

• The DEF dosing valve joints between the valve and the valve assembly body.

Due to deposit buildup possibly masking the source of the leak, it may be necessary to remove the deposits and clean the area with warm water.

NOTE: The aftertreatment DEF dosing system will not prime until the correct SCR temperatures are reached.  Test drive the vehicle for a minimum of 15 minutes to get the SCR system up to temperature. Check the area again for the source of the leak.

Once the source of the DEF leaks and/or deposits are identified, reference the Clean and Inspect for Reuse section of this procedure.

Inspect the dosing valve body and coolant fittings at the aftertreatment DEF dosing valve.

Visually check for signs of leaks and/or deposits.

If the aftertreatment DEF dosing valve is suspected to be leaking coolant, and the source of the coolant leak can not be identified, pressurize the cooling system. Refer to Procedure 008-018 in Section 8.

If leaks and/or deposits are identified, reference the Clean and Inspect for Reuse section of this procedure, after the connections are removed.

Service Tip:  If removal of the coolant fittings and/or heat shield is necessary, remove or loosen the coolant fitting prior to removing the aftertreatment DEF dosing valve.  Reference the Preparatory and Disassemble sections of this procedure.

Inspect the body and around the base of the aftertreatment DEF dosing valve. Look for signs of exhaust leaks and white deposits.

If leaks and/or deposits are identified, reference the Clean and Inspect for Reuse section of this procedure.

Use a multimeter to check the resistance of the aftertreatment DEF dosing valve. Use the following procedure for general resistance measurement techniques. Refer to Procedure 019-360 in Section 19.

NOTE: Repair connector, Part Number 3164098, can be used as a test lead.

Resistance Specification:  12 ± 0.6 ohms

The resistance must be measured at room temperature, around 25°C [77°F]. If the measured value is not within specification, replace the aftertreatment DEF dosing valve. If the measured resistance is out of specification, the aftertreatment DEF dosing valve may have been overheated.

Visually check the outside of the aftertreatment DEF dosing valve for signs of discoloration from excessive heat.

Inspect for inadequate or lack of coolant flow to the aftertreatment DEF dosing valve. Verify there are no leaks, blockages, or restrictions in the coolant suppy and return lines, between the engine and the aftertreatment DEF dosing valve.

To check the coolant passages internal to the aftertreatment DEF dosing valve, reference the Clean and Inspect for Reuse section of this procedure.

WARNING  Diesel exhaust fluid (DEF) contains urea.  Do not get the substance in your eyes. In case of contact, immediately flush eyes with large amounts of water for a minimum of 15 minutes. Do not swallow. In the event the diesel exhaust fluid is ingested, contact a physician immediately. Reference the Materials Safety Data Sheet (MSDS) for additional information.

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

WARNING  During regeneration, the exhaust gas temperature could reach 800°C [1500°F], and the exhaust system surface temperature could exceed 700°C [1300°F], which is hot enough to ignite or melt common materials, and to burn people. The exhaust and exhaust components can remain hot after the vehicle has stopped moving. To avoid the risk of fire, property damage, burns or other serious personal injury, allow the exhaust system to cool before beginning this procedure or repair and make sure that no combustible materials are located where they are likely to come in contact with hot exhaust or exhaust components.

WARNING  The diesel exhaust fluid line connecting the aftertreatment diesel exhaust fluid dosing unit to the aftertreatment diesel exhaust fluid dosing valve is under low pressure and should not be disconnected while the engine is running, or before the system has completed the purge process, after engine shutdown.  Disconnecting the diesel exhaust fluid line while under low pressure could cause diesel exhaust fluid to spray.

NOTE: Do not disconnect the vehicle batteries until the DEF dosing system has completed the purge cycle.  Before beginning to remove and/or disconnect any components, wait at least 5 minutes after the keyswitch is turned OFF for the aftertreatment DEF dosing system to purge the DEF from the system. The purge cycle is an automatic process and does not require intervention to occur. The aftertreatment DEF dosing unit will create an audible pumping noise during the purging process.

• Disconnect the batteries. Refer to the OEM service manual.

Do not drain the cooling system.  Use one of the following two methods to prevent draining the cooling system, when the aftertreatment DEF dosing valve coolant lines are disconnected.

NOTE: The coolant supply and DEF lines are supplied by the OEM. The removal of the lines can vary by OEM. The fittings on the aftertreatment DEF dosing valve are set up for quick disconnect style fittings.

NOTE: Prior to using this method, inspect the aftertreatment DEF dosing valve coolant lines to be sure they are flexible hose material and will not be damaged when using cooling hose pinch-off pliers.

Method Number 1:

• Use cooling hose pinch-off pliers to clamp one of the aftertreatment DEF dosing valve coolant lines.
• Disconnect the coolant lines.  Refer to the OEM service manual.
• Insert a cooling line plug, Part Number 4919576, into the disconnected coolant line.  The cooling hose pinch-off pliers can be removed.
• Repeat these steps for the other coolant line.

Method Number 2:

• Determine the appropriate radiator or coolant expansion tank cap adapter for the vehicle being serviced. The list of available caps and applications can be found in Section 14 of the Service Products Catalog.
• Install the adapter on the radiator or coolant expansion tank.  Connect an automotive hand held vacuum pump, and apply 76 mm Hg [3 in Hg] of vacuum.

NOTE: Depending on the cooling system configuration, more vacuum may be required to keep the cooling system in balance on systems where there is a significant height difference between the aftertreatment DEF dosing valve and the radiator or coolant expansion tank fill location.

NOTE: The coolant supply and DEF lines are supplied by the OEM. The removal of the lines can vary by OEM.  The fittings on the aftertreatment DEF dosing valve are set up for quick disconnect style fittings.

• Place a container under the aftertreatment DEF dosing valve. There may be a small quantity of coolant that drains from the coolant lines when they are disconnected.
• Disconnect the coolant lines.  Refer to the OEM service manual.
• Insert cooling line plugs, Part Number 4919576, into each of the disconnected coolant lines.
• The vacuum pump can be removed.

WARNING  Wear appropriate eye and face protection when using compressed air. Flying debris and dirt can cause personal injury.

Use compressed air to blow away any debris from around the aftertreatment DEF dosing valve and connections.

Make sure to clean away any debris trapped in the gaps between the aftertreatment diesel exhaust fluid dosing valve and the decomposition tube. This is to be sure debris does not fall into the decomposition tube during the removal of the aftertreatment DEF dosing valve.

If there are any white deposits on the DEF line connection, wipe away the deposits with a clean shop towel, soaked in warm water.

CAUTION  Care should be taken when handling and/or disconnecting the diesel exhaust fluid line from the aftertreatment diesel exhaust fluid dosing valve. The intake of the aftertreatment diesel exhaust fluid dosing valve is plastic and can be easily damaged.

NOTE: Protect the coolant and diesel exhaust fluid ports with plastic caps to prevent entrance of dirt and debris.

Place a small plastic container under the aftertreatment DEF dosing valve to catch any residual DEF prior to disconnecting the DEF supply line. Disconnect the connections at the aftertreatment DEF dosing valve in the following order:

1. Disconnect the DEF line.  Refer to the OEM service manual.
2. Disconnect the 2-pin electrical connector. Press the tab on the electrical connector and pull to disconnect.

After the electrical connection is disconnected, cover the connection on the aftertreatment DEF dosing valve with electrical tape to prevent any DEF from getting into the electrical connection.

Remove the capscrews that mount the aftertreatment DEF dosing valve to the decomposition tube.

Remove the aftertreatment DEF dosing valve.

NOTE: The aftertreatment DEF dosing valve gasket may stick to the aftertreatment decomposition tube when the aftertreatment DEF dosing valve is removed.

Use a flat blade screwdriver to carefully pry up the tabs that hold the gasket to the aftertreatment DEF dosing valve.

Remove and discard the gasket. The gasket is not reusable.

NOTE: The aftertreatment DEF dosing valve should only be disassembled if a symptom has been identified that indicates further investigation is required.

Remove the two coolant fittings from the aftertreatment diesel exhaust fluid dosing valve.

Remove and discard the o-rings from the coolant fittings.

Remove the heat shield.

NOTE: Do not remove the DEF dosing valve (1) from the assembly (2). It is not a serviceable part.

If leaks and/or deposits were found during the Initial Check section of this procedure, at the DEF dosing valve joints between the valve and the valve assembly body, replace the aftertreatment DEF dosing valve. If leaks and/or deposits were found at the DEF line connection, inspect the DEF line connection port for cracks or pitting.

NOTE: If damage and/or corrosion is found, also inspect the DEF line connection. Refer to the OEM service manual.

Inspect the electrical connector and pins for damage or corrosion. Use the following procedure for general inspection techniques. Refer to Procedure 019-361 in Section 19.

If damage or corrosion is found, also inspect the electrical connector and pins on the vehicle harness.  Refer to the OEM service manual.

Replace the aftertreatment DEF dosing valve if any damage is found.

The heat shield and coolant fittings are serviceable items of the aftertreatment DEF dosing valve.

If leaks or deposits were found at the coolant line connections during the Initial Check section of this procedure, inspect the coolant fittings for cracks and signs of corrosion and/or pitting.

If corrosion is found, the coolant may be contaminated and/or the concentration incorrect. Inspect the coolant. Refer to the Cummins® Coolant Requirements and Maintenance, Bulletin 3666132.

If damage or corrosion is found, also inspect the coolant line connector(s).  Refer to the OEM service manual.

Inspect the base of the coolant fittings.

Inspect the heat shield for cracks or heavy corrosion. Replace as required. Reference the Disassemble section of this procedure.

If the coolant fittings were removed from the aftertreatment DEF dosing valve assembly, visually check the threads and o-ring sealing surfaces of the coolant fittings and the coolant ports in the aftertreatment DEF dosing valve assembly for pitting and corrosion.

Clean with an abrasive pad, Part Number 3823258 or equivalent, and a clean cloth.

If the pitting and/or corrosion can not be removed using the abrasive pad, replace the component.

WARNING  When using solvents, acids, or alkaline materials for cleaning, follow the manufacture’s recommendations for use. Wear goggles and protective clothing to reduce the possibility of personal injury.

WARNING  Wear appropriate eye and face protection when using compressed air. Flying debris and dirt can cause personal injury.

CAUTION  Do not submerge the aftertreatment diesel exhaust fluid dosing valve in solvent or water. Damage to the aftertreatment diesel exhaust fluid dosing valve will result.

If not already removed, remove the coolant fittings from the aftertreatment diesel exhaust fluid dosing valve. Reference the Disassemble section of this procedure.

Clean the aftertreatment DEF dosing valve coolant passages with a safety solvent. Use a pipe cleaner to clean the passageways.

With the aftertreatment DEF dosing valve positioned so that the coolant ports are pointing up, pour safety solvent in one coolant port, until the safety solvent begins to flow out of the opposite port.

Tip the aftertreatment DEF dosing valve so that the safety solvent will flow out of the opposite port. Verify that the safety solvent flows out of the other port in one continuous stream.

If safety solvent does not flow in one continuous stream, the coolant passage may still be restricted or blocked. Repeat the cleaning process until the safety solvent flows out in one continous stream. If the safety solvent will not flow in a continuous stream, replace the aftertreatment DEF dosing valve.

Dry with compressed air.

CAUTION  Use only a nylon brush to clean the tip of the aftertreatment diesel exhaust fluid dosing valve. The use of a wire brush or a wire wheel will cause permanent damage to the aftertreatment diesel exhaust fluid dosing valve.

Use a nylon brush and warm distilled water to clean the bottom and tip of the aftertreatment DEF dosing valve.

Wipe away any debris with a clean shop towel soaked in distilled water.

Inspect the DEF dosing valve tip for cracks or other damage. Replace the valve if cracks or other damage is found.

If leaks and/or deposits were found at the base of the aftertreatment DEF dosing valve during the Initial Check section of this procedure, inspect the following items:

• The bottom of the aftertreatment DEF dosing valve, around the gasket sealing surface, for signs of heavy corrosion, pitting, and/or surface damage.  Replace the aftertreatment DEF dosing valve if any damage is found.
• The aftertreatment DEF dosing valve mounting surface on the decomposition tube. Use the following procedure for further cleaning and inspection information. Refer to Procedure 011-062 in Section 11.

If replacing the aftertreatment DEF dosing valve, make sure to transfer the protective caps from the replacement aftertreatment DEF dosing valve to the old aftertreatment DEF dosing valve prior to installing the core in the return box.

Make sure to fill out any requested information (ESN, mileage, VIN, etc.).

Inspect the capscrews for damaged threads, corroded surfaces, or a reduced diameter (due to capscrew stretching).

Replace the capscrews if any damage is found.

Install new o-rings onto the two coolant fittings.

Lubricate the o-rings with assembly lubricant, Part Number 3163086.

Install the heat shield.

Install the coolant fittings onto the aftertreatment DEF dosing valve.

Tighten the coolant fittings.

Service Tip:  If removal of the coolant fittings and/or heat shield was necessary, install the coolant fittings after installing the aftertreatment DEF dosing valve.

Install a new gasket on the bottom of the aftertreatment DEF dosing valve.

Center the gasket over the bottom of the aftertreatment DEF dosing valve, then snap the gasket into place.

Verify that each of the three locking tabs have locked into the groove.

Install the aftertreatment DEF dosing valve onto the decomposition tube.

Apply a coat of high temperature anti-seize compound to the aftertreatment DEF dosing valve mounting capscrews.

Install the aftertreatment DEF dosing valve mounting capscrews.

Tighten the capscrews.

NOTE: Remove any protective caps and/or covers from the electrical, coolant, and DEF ports just prior to connecting.

Connect the 2-pin electrical connector to the aftertreatment DEF dosing valve.

NOTE: The coolant supply and DEF lines are supplied by the OEM. The installation of the lines can vary by OEM.  The fittings on the aftertreatment DEF dosing valve are set up for quick disconnect style fittings.

Use the same method as utilized in the Preparatory Steps section of this procedure to prevent draining the cooling system when the aftertreatment DEF dosing valve coolant lines are disconnected. 

Remove the coolant line plugs, Part Number 4919576, from each of the disconnected coolant lines.

Connect the coolant supply and return lines.  Refer to the OEM service manual.

Remove all tools used.

Connect the DEF line.  Refer to the OEM service manual. 

Once all of the connections are made, give each line a slight pull to make sure each is securely installed.

WARNING  Batteries can emit explosive gases. To reduce the possibilityof personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

CAUTION  Do not use the flow test portion of INSITE™ electronic service tool Diesel Exhaust Fluid Doser Pump Override Test to check the system for leaks.  This will spray DEF into the exhaust system at too low of a temperature to evaporate, resulting in deposit formations in the exhaust system.

NOTE: If any coolant was spilled, check the coolant level.  Fill the cooling system as required. Refer to Procedure 008-018 in Section 8.

• Connect the vehicle batteries. Refer to the OEM service manual.
• Operate the engine and check for leaks.

NOTE: The aftertreatment DEF dosing system will not prime until the correct SCR temperatures are reached.  To verify that the system is correctly installed and does not leak, test drive the vehicle for a minimum of 15 minutes to get the SCR system up to temperature.