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 4310-11-12 ( OEM Part Number 21640012 ). 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, 11"
OEM NUMBERS
| Primary OEM | 21640012 |
| Additional OEM | 21640012 |
ADDITIONAL DETAILS
| CONDITION | Remanufactured |
| UPC / Barcode | 00840490540088 |
| 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.
Reliable emissions control begins with the MI-Jack Products Cummins ISB 6.7L DEF Head Unit: OEM 21640012, a direct-fit solution for compatible MI-Jack machinery. Manufactured to OEM standards, this unit monitors diesel exhaust fluid levels, temperature, and quality to ensure compliance and consistent aftertreatment performance. Its durable construction is built to handle demanding operating conditions, protecting both the exhaust system and overall engine efficiency. By choosing an OEM DEF head unit, you help prevent compatibility concerns and ensure dependable service life. This component is a proven choice for keeping MI-Jack Cummins-powered equipment operating smoothly and without interruption.
PEOPLE ALSO ASKS | BLOG(S)
The DEF (Diesel Exhaust luid) Head Unit, part number 21640012, is fitted into MI‑Jack equipment powered by the Cummins ISB 6.7L engine. Its operation is central to the engine’s emissions control system, specifically for managing how and when DEF is used in the exhaust aftertreatment process.
Key Operational Functions
- Fluid Level Monitoring:
- The unit detects and reports how much DEF fluid is in the tank. When levels get low, it sends data to the engine control module (ECM) so that the operator or system can take action.
- Temperature Sensing:
- It senses the temperature of the DEF. Since DEF must stay within certain temperature ranges (because it freezes below a threshold), this function ensures the system knows when heating or protective measures are needed.
- Fluid Suction & Return Management:
- The head unit includes plumbing for pulling DEF from the tank, sending it to the dosing or injection module, and returning unused fluid or conditioned DEF when required. This ensures a stable, reliable supply of DEF to the exhaust path.
- Filtering or Screening:
- Before the DEF fluid leaves the tank, the head unit typically filters it to remove particulates or contamination. Clean fluid is essential to prevent clogging in downstream components.
- Sensor Feedback to Engine Controls:
- The sensors in the head unit transmit data (level, temperature, possibly quality) to the ECM. If readings fall outside acceptable ranges (too low, too cold, etc.), warning signals or engine derate protections may be triggered.
A properly functioning DEF Head Unit like OEM 21640012 is crucial for maintaining emissions compliance and engine health. If the unit fails or provides incorrect sensor data, the engine may lose power, trigger warnings, or fail emission tests. Keep the head unit operating well by using clean DEF, ensuring sensors are functional, and replacing the unit if degradation occurs.
The DEF head unit in the Cummins ISB 6.7L engine, including OEM part number 21640012 used in MI-Jack Products and similar equipment, is a critical component in the emissions system. It monitors DEF level, quality, and temperature to keep your system compliant with emission regulations.
Expected Lifespan of OEM 21640012
Under normal operating conditions, the DEF head unit typically lasts between 100,000 and 200,000 miles, or about 3 to 7 years. However, its lifespan depends heavily on operating environment, fluid quality, and maintenance practices.
What Shortens the Lifespan?
- Contaminated DEF fluid
- Can corrode internal components
- Extreme temperatures
- Heat and freezing impact sensor accuracy
- Improper storage or usage
- Leads to crystallization and clogging
- Faulty wiring or connectors
- Can interrupt signals and damage the unit
- Lack of system checks
- Missed inspections allow small issues to grow
Keeping the DEF system clean and serviced regularly will help you get the most out of your DEF head unit. When signs like false level readings or DEF system warnings appear, it may be time to inspect or replace the unit.
Yes, in some cases it can trigger derates or shutdowns to protect emissions compliance.
Yes, it is a direct OEM replacement designed for simple installation.
It is built to endure extreme conditions typical of heavy-duty equipment use.
Delays may lead to failed emissions tests, reduced performance, and downtime.
Cummins DEF Head Units
