MI-Jack Products Cummins ISB 6.7L DEF Head Unit
MI-JACK PRODUCTS CUMMINS ISB 6.7L DEF HEAD UNIT
ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY
WARRANTY
1M MILES OR 1 YEAR
PRODUCT DESCRIPTION
This is a Remanufactured, Tamerx DEF Head Unit, Tamerx part number 4310-22-6 ( OEM Part Number 21640011 ). This part is primarily made for a Cummins ISB 6.7L, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here
Additional Notes: DEF Header, 40 MICRON, 22"
OEM NUMBERS
| Primary OEM | 21640011 |
| Additional OEM | 21640011 |
ADDITIONAL DETAILS
| CONDITION | Remanufactured |
| UPC / Barcode | 00840490540835 |
| WEIGHT | 8.00 LBS |
SHIPPING OPTIONS
Ship Weight : 8.00 LBS
UPS Ground, 2nd Day Air, Next Day Air
SHIPPING POLICY
Tamerx Diesel Products ships via UPS Ground. Next day air shipping can be arranged for a reasonable price of anywhere from $50.00 - $100.00 depending on the weight of the product and your location. We will do everything we can to make sure that you get the service you need. We understand how important it is to receive your order as quickly as possible.
In most cases Tamerx Diesel Products only needs one address, as long as your product is shipping to the same location as your billing information. In order to eliminate credit card fraud, your billing information must match the credit card you provide.
The terms, conditions, and details of our warranty vary from product to product. Specific warranty details can be found below.
Tamerx Diesel Products provides a replacement warranty on all of our parts. The duration and mileage limitations of the warranty vary by product and are specified on the product's detail page/item listing.
Please note that the warranty covers replacement of the part and the cost of shipping the replacement part to you only. It does not cover any shop, labor, towing, or any similar or related costs. This is not a "money back guarantee".
If you experience a problem with your part or it is not functioning properly, the correct warranty procedure is to call us at (510) 257-1777 (8:00 AM - 5:00 PM ET Monday through Friday). Be sure to have your order number and/or other relevant order information ready so we can easily locate your order and resolve your issue as quickly as possible. From that point, we will review with you any troubleshooting steps that may need to be taken and other areas or systems that can be checked to rule out external problems contributing to your part's issue. If a replacement is determined to be necessary, we will then arrange for your replacement part to ship out ASAP and issue any necessary return shipping labels and/or documents.
As is the case for the majority of the diesel products sold on Tamerx Diesel Products, your part's warranty is active as soon as you install it. In some other cases, warranty activation is contingent upon you sending us your core (i.e., your old part). Tamerx Diesel Products will provide you a return shipping label for parts that have a warranty with a core return condition. When we have received your core return, the part's warranty coverage begins. We reserve the right to void the product warranty if your core is not received within the allotted time, or if it isn't received at all. If the warranty for the diesel part you are purchasing has a core return requirement, it will be clearly noted on the product detail page/item listing.
What is a Core Charge?
A core charge (also called "core deposit") is similar to the deposit you might pay for a can or bottle of soda and is a standard requirement in the auto parts industry. For example, in many states, to promote recycling, you pay a deposit when you purchase a can of soda and receive your deposit back when you return the empty can. Many automotive parts have a core charge, or core price, that works in essentially the same way as a soda can deposit.
30 Day Core Charge Hold
You authorize Tamerx Diesel Products, to hold your credit card for the specified core charge amount and that you agree to return your core with 30 days of receiving the purchased part. When we have received your core return, the hold is released and the core charge payment is canceled.
The customer, or parts buyer, is responsible for any shipping costs associated with core returns unless otherwise specified in the product listing/detail page. Tamerx Diesel Products offers prepaid UPS shipping labels (SKU numbers UPS-CR1 and UPS-CR2) for use in returning your core that are available for purchase on our website during your shopping/order process.
The shipping label you will need to use for the core return is dependent upon what part you are purchasing. UPS-CR1 is good for cores weighing up to 20 pounds. UPS-CR2 is appropriate for shipping cores weighing 21 pounds or more. You must include enough information with the core return that clearly identifies it as a.) a Core Return, and b.) contains enough information we can use to clearly associate the core return with your order. Including a copy of the invoice or packing slip that came with the original shipment, clearly marked "Core Return", is ideal. Alternately, you can include a note marked as "Core Return" that includes your order number, full name and address, and phone number or other contact information. Failure to include this information with your returned core will most likely delay any due core credit being issued and/or delay any applicable warranty activation. Core returns need to be for the exact part purchased and cannot be damaged. Substituting another part in place of the part you have purchased is not acceptable.
All fluids must be drained.
If you have purchased a set or a parts package, you will need to return cores for all components of the set. For example, if you have purchaed a high pressure oil pump with an IPR valve, you will need to return both HPOP and IPR valve cores to receive proper credit. If you have purchased an EGR cooler/EGR valve package, your core return must consist of an EGR cooler core and an EGR valve core, or core credit will not be given.
Core Charges are often mandated by state legislature, and, as such, the actual core charge and taxes on the charge may vary depending on the state in which you buy your part. The Tamerx Diesel Products core charge presented to you online today with your item is representative of the most common core charge.
Ensure accurate DEF system monitoring with the MI-Jack Products Cummins ISB 6.7L DEF Head Unit (OEM 21640011). This genuine OEM component is designed to measure diesel exhaust fluid level, temperature, and quality, providing precise data to maintain proper emissions system function. Built to meet Cummins and MI-Jack specifications, it ensures reliable communication with the engine’s aftertreatment system for efficient and compliant operation. The durable, weather-resistant design offers long-lasting performance even in demanding industrial environments. Rely on Tamerx Diesel Products LLC for authentic DEF system replacement parts that deliver consistent reliability, accuracy, and durability for your Cummins ISB 6.7L-powered equipment.
PEOPLE ALSO ASKS | BLOG(S)
This DEF Head Unit is a module for the Diesel Exhaust Fluid (DEF) system used in Cummins ISB 6.7 L applications in MI-Jack equipment. It manages and monitors the DEF fluid paths, sensors and communication to ensure the after-treatment (SCR) system works properly.
Key Components
- Housing / Mounting Frame
- The structural body that mounts to the DEF tank or system, holding all internal components securely.
- Fluid Header / Manifold with Filter
- This part routes the DEF fluid and usually includes a filter rated (for example) at 40 microns to remove contaminants before the fluid is used.
- Level Sensor
- Detects how much DEF fluid remains in the tank so the system knows when to alert or refill.
- Temperature Sensor
- Monitors the fluid temperature to avoid issues like freezing or improper fluid properties under extreme conditions.
- Pressure or Flow Sensor
- Monitors either fluid pressure or flow in the system to ensure correct delivery and dosing of DEF.
- Electrical Connector / Harness Interface
- The wiring connection that sends sensor signals to the engine control/after-treatment module for monitoring and control.
- Inlet & Outlet Ports / Plumbing Interfaces
- The fittings where the DEF fluid enters and exits the head unit, including lines to the dosing system or SCR components.
- Seals, Gaskets & Filter Element
- Internal seals and gaskets prevent leaks; the filter element protects the system from debris or crystallized DEF.
Each component plays a role in ensuring the DEF system functions reliably. The level and temperature sensors let the control system monitor the fluid’s condition; the fluid header and filter manage delivery and cleanliness; the plumbing and connectors tie it all into the vehicle’s systems. If any component fails or is compromised, you risk incorrect dosing, system faults, or emissions non-compliance.
Driving with a bad Diesel Exhaust Fluid (DEF) head unit is not recommended. The DEF head unit monitors critical information — such as fluid level, temperature, and quality — to ensure your vehicle’s emissions system runs correctly. When this component fails, it can cause inaccurate readings, warning lights, and eventually engine limitations.
Initially, you might notice a Check Engine Light or DEF system warning. If ignored, the issue can quickly escalate as the vehicle’s computer can’t verify DEF conditions. To comply with emissions standards, the system may enter derate mode, drastically limiting engine power and speed — sometimes to as low as 5 mph.
Key risks of driving with a bad DEF head unit include:
- Sudden power loss
- from derate mode
- False DEF level readings
- leading to unexpected shutdowns
- Emission system malfunction
- or potential component damage
- Costly repairs or towing expenses
- if the vehicle becomes disabled
If you suspect a failing DEF head unit, it’s best to have it diagnosed and replaced immediately. Prompt repair prevents unnecessary downtime, ensures emissions compliance, and keeps your diesel vehicle running reliably.
It monitors Diesel Exhaust Fluid (DEF) level, temperature and pressure; and controls DEF dosing into the SCR system to reduce emissions.
Signs include DEF system fault codes, inaccurate or missing readings for DEF level/temperature/pressure, or SCR/engine derate events.
Power down equipment, relieve DEF system pressure, clean out any crystallized DEF from the tank, inspect wiring/connectors, and clear the mounting port.
Clear all fault codes, monitor live data for DEF level, temperature and pressure via diagnostic tool, and confirm no new fault codes appear.
Cummins DEF Head Units
