Oshkosh Cummins ISB 6.7L, B6.7 DEF Head Unit
OSHKOSH CUMMINS ISB 6.7L, B6.7 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 2321-18-4 ( OEM Part Number A000P868 ). This part is primarily made for a Cummins ISB 6.7L, B6.7, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here
Additional Notes: DEF Header, 449mm
OEM NUMBERS
| Primary OEM | A000P868 |
| Additional OEM | A000P868 |
ADDITIONAL DETAILS
| CONDITION | Remanufactured |
| UPC / Barcode | 00840490541139 |
| 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.
The Oshkosh Cummins ISB 6.7L, B6.7 DEF Head Unit OEM A000P868 is a factory-original component designed to ensure proper function of the Diesel Exhaust Fluid system. Built to meet Cummins specifications, this head unit provides accurate fitment and dependable operation for ISB 6.7L and B6.7 engines. Its role in the emissions system supports compliance with environmental standards while helping maintain smooth, consistent engine operation. Constructed with durability in mind, it stands up to the rigorous demands of Oshkosh equipment applications. As an OEM replacement, this DEF head unit offers the reliability and service life that operators can trust to keep their machines operating efficiently.
PEOPLE ALSO ASKS | BLOG(S)
Modern diesel engines rely on advanced emissions systems to stay compliant, and the DEF (Diesel Exhaust Fluid) Head Unit is at the center of this process. For the Oshkosh Cummins ISB 6.7L / B6.7 engine, the OEM A000P868 DEF Head Unit serves as the critical “smart” component inside the DEF tank.
What the DEF Head Unit Does
The DEF Head Unit is more than just a sensor—it’s a multifunctional device that keeps the aftertreatment system operating reliably. Its core functions include:
- Measuring DEF level
- so the system knows when fluid is running low.
- Monitoring fluid quality
- to ensure the DEF meets required chemical standards.
- Tracking temperature
- to help prevent freezing or overheating of the fluid.
- Communicating with the ECM
- (engine control module) to relay data and trigger alerts.
The unit sits inside the DEF tank and continuously collects information. Sensors measure the level, temperature, and quality of the fluid, while integrated heaters prevent the DEF from freezing in cold conditions. This information is sent to the ECM, which uses it to adjust engine operation and maintain emissions compliance.
Without the OEM A000P868 DEF Head Unit, the Cummins ISB 6.7L / B6.7 engine would not be able to properly regulate its emissions system. By combining multiple sensors and a heating function, it ensures reliability, efficiency, and environmental compliance in every application.
The DEF (Diesel Exhaust Fluid) head unit plays a crucial role in today’s emission systems. It measures fluid quality, temperature, and level, ensuring everything operates within compliance. But many drivers ask the same question: how long should a DEF head unit actually last?
Typical Lifespan of a DEF Head Unit
On average, a DEF head unit lasts 5 to 7 years depending on vehicle use, environmental conditions, and maintenance practices. Some units may fail earlier due to contamination or improper handling of DEF fluid.
Factors That Affect Longevity:
- Quality of DEF fluid
- only certified DEF should be used
- Storage conditions
- DEF exposed to heat or freezing can cause crystallization
- Refill practices
- Introducing dirt or debris during refills shortens lifespan
- Operating environment
- Extreme weather and heavy-duty cycles create added stress
The best way to maximize lifespan is through preventive care. Always use fresh, uncontaminated DEF, keep storage containers sealed, and inspect the DEF tank regularly. By reducing contamination and extreme wear, you can help ensure your head unit lasts closer to the upper end of its expected range.
It monitors DEF tank levels, temperature, and quality to support proper emissions system function.
A failed DEF head unit can cause warning lights, fault codes, and limited engine operation until replaced.
Yes, a faulty unit may trigger DEF-related fault codes and limit vehicle operation.
Common signs include error codes, DEF warning lights, or inaccurate DEF readings.
Cummins DEF Head Units
