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Cummins ISB 6.7L Doser DEF Pump : OEM 91894B01

CUMMINS ISB 6.7L DOSER DEF PUMP : OEM 91894B01

Shipping ICON

ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY

WARRANTY ICON

WARRANTY
1M MILES OR 1 YEAR

$695.00

CORE CHARGE:

$250.00
iCORE DISCLAIMER: The CORE charge is a 30 day hold and will not be processed as long as the CORE is returned within 30 days. If you do not have a CORE or fail to return the CORE within 30 days, the CORE charge hold amount will be processed at that time.

AVAILABILITY IN STOCK
OEM NUMBER91894B01
PART TYPEDoser DEF Pump
BRANDTamerx Diesel Products
ENGINE MAKECummins
ENGINE TYPEISB 6.7L
YEAR
PART NUMBER91894B01-DMP
APPLICATION NOTESTigercat

PRODUCT DESCRIPTION

This is a Remanufactured Tamerx Doser DEF Pump, Tamerx part number 91894B01-DMP ( OEM Part Number 91894B01 ). All parts are proudly remanufactured in the U.S.A. to the highest of OEM standards, and improvements are often applied to the original design in the remanufacturing process. 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

OEM NUMBERS

Primary OEM 91894B01
Additional OEM 91894B01

ADDITIONAL DETAILS

CONDITION Remanufactured
UPC / Barcode 00840490536470
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.


Designed for use in Cummins ISB 6.7L aftertreatment systems, OEM 91894B01 is a DEF doser pump engineered to meter and supply Diesel Exhaust Fluid into the SCR assembly with controlled precision. This component is manufactured to OEM specifications to ensure accurate fitment and compatibility with factory-installed dosing and exhaust components. Built from durable materials, it is suited for the operating environments common in medium- and heavy-duty diesel applications. The pump supports consistent DEF flow to help maintain proper emissions system function. It is a reliable choice for fleet service and targeted repair needs requiring dependable aftertreatment performance.

PEOPLE ALSO ASKS | BLOG(S)

The Cummins ISB 6.7L Doser DEF Pump: OEM 91894B01 is a key component of the Selective Catalytic Reduction (SCR) system. It is responsible for drawing, pressurizing, and delivering Diesel Exhaust Fluid (DEF) to the doser injector. Although serviced as a complete unit, the pump assembly contains several integrated components that allow it to function accurately and reliably.

Below are the primary components typically found within this DEF pump assembly:

  • Pump housing
    • The main structural body that encloses and protects internal components.
  • Electric drive motor
    • Powers the internal pumping mechanism that moves DEF from the tank.
  • Internal pump mechanism (diaphragm or piston-style unit)
    • Creates pressure to deliver DEF at the correct flow rate.
  • Pressure sensor
    • Monitors DEF pressure and sends feedback to the engine control module (ECM).
  • Internal control valve
    • Regulates DEF flow based on commands from the ECM.
  • Electrical connector
    • Connects the pump to the vehicle’s wiring harness for communication and control.
  • Inlet and outlet ports
    • Allow DEF to enter from the tank and exit toward the dosing injector.
  • Seals and O-rings
    • Prevent leaks and protect against contamination.

Together, these components allow OEM 91894B01 to supply DEF accurately and consistently, ensuring proper NOx reduction and reliable emissions system performance in Cummins ISB 6.7L applications.

The main cause of DEF doser pump failure is DEF contamination and crystallization inside the pump assembly. The doser pump is responsible for pressurizing Diesel Exhaust Fluid and delivering it to the injector. When DEF quality is compromised or the system is not properly maintained, internal components can become restricted or damaged.

Contaminated DEF—especially fluid mixed with dirt, fuel, coolant, or water—can damage seals, clog internal passages, and cause premature wear of the pump motor and pressure components. Over time, crystallized DEF buildup can restrict flow and prevent the pump from building or holding proper pressure.

Midway through diagnosis, the most common contributing factors to DEF doser pump failure include:

  • Use of non-ISO 22241 compliant DEF
  • DEF contamination during storage or filling
  • Crystallization from incomplete purge cycles
  • Running the DEF tank dry
  • Clogged DEF filters or restricted lines
  • Electrical connector corrosion or voltage issues

In many cases, the pump itself is not defective by design. Poor DEF handling practices, neglected maintenance, or unresolved SCR system issues lead to premature failure.

Consistent use of high-quality DEF, proper storage, routine system inspection, and immediate correction of dosing or pressure faults are essential to preventing DEF doser pump failure and maintaining reliable SCR system performance.

Yes, it interfaces with the engine control module and DEF sensors for proper dosing regulation.

Heavy-duty trucks and commercial vehicles equipped with Cummins ISB 6.7L engines use this DEF pump.

Yes, a diagnostic scan is typically recommended after installation to confirm correct communication with the DEF system.

Yes, professional installation is recommended to ensure proper fluid line connections and correct integration with the emissions system.

Cummins Doser DEF Pumps