Loading...

Navistar/International Cummins ISX15, X15 DEF Head Unit

NAVISTAR/INTERNATIONAL CUMMINS ISX15, X15 DEF HEAD UNIT

Shipping ICON

ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY

WARRANTY ICON

WARRANTY
1M MILES OR 1 YEAR

$500.00

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 NUMBER4352100C92
PART TYPEDEF Head Unit
BRANDTamerx Diesel Products
ENGINE MAKECummins
ENGINE TYPEISX15, X15
YEAR2017-2024
PART NUMBER2321-22-1
APPLICATION NOTESNavistar/International
ADDITIONAL NOTESQLS DEF Header

PRODUCT DESCRIPTION

This is a Remanufactured, Tamerx DEF Head Unit, Tamerx part number 2321-22-1 ( OEM Part Number 4352100C92 ).This part is primarily made for a Cummins ISX15, X15, production years 2017-2024, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here

Additional Notes: QLS DEF Header

OEM NUMBERS

Primary OEM4352100C92
Additional OEM2510966C1, 2510966C3, 2515986C1, 2515987C1, 2517604C1, 2523591C91, 4086046C91, 4097728C91, 4140918C91, 4254210C91, 4352100C92

ADDITIONAL DETAILS

CONDITIONRemanufactured
UPC / Barcode00840490541160
WEIGHT8.00 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.


Dominate the road with the Navistar / International Cummins ISX15 / X15 DEF Head Unit — precision-tuned for seamless integration and peak emissions control. Engineered to deliver real-time monitoring of DEF level, temperature, and quality, this rugged, OEM-grade unit keeps your SCR system optimized and your operation compliant. Designed to prevent derates under pressure, it’s the reliable performance boost your big rig deserves mile after mile.

FITMENT CHART

YEARMAKEENGINE(S)
2017Cummins ISX15 X15
2018Cummins ISX15 X15
2019Cummins ISX15 X15
2020Cummins ISX15 X15
2021Cummins ISX15 X15
2022Cummins ISX15 X15
2023Cummins ISX15 X15
2024Cummins ISX15 X15

PEOPLE ALSO ASKS | BLOG(S)

Operating a Navistar or International rig with a Cummins ISX15 (or X15) engine means you depend heavily on your aftertreatment system to stay compliant—and that places significant importance on one component: the DEF (Diesel Exhaust Fluid) head unit. A properly functioning DEF head ensures the engine control module receives accurate fluid readings and doses, which helps prevent fault codes, system warnings, or engine derates.

  • Measures DEF fluid properties including temperature, level, and urea concentration and feeds that information back to the ECU

  • Manages precise DEF dosing into the exhaust stream to ensure the SCR (Selective Catalytic Reduction) system can effectively reduce NOx emissions

  • Designed to OEM tolerances for ISX15 / X15 applications—meaning it’s built for direct fit and calibration

  • Helps avoid emissions fault codes, check engine alerts, and derate conditions that often stem from sensor inaccuracies

  • Built durable to withstand vibration, thermal cycling, and exposure to DEF fluid’s corrosive elements

  • Users can replace it in the field with minimal downtime, restoring system integrity

When signs of trouble emerge—like a “DEF system error” or unexpected engine derate—the DEF head is often the underlying culprit. Installing a correct, matching DEF Head Unit for your Navistar / International Cummins ISX15 / X15 helps maintain consistent emissions performance, prevent surprise faults, and keep your rig road-ready. Don’t let a failing sensor become the bottleneck in your emissions system.

The DEF (Diesel Exhaust Fluid) head unit monitors fluid level, quality, and temperature, making it a vital part of a diesel emissions system. When it begins to malfunction, many operators wonder whether cleaning the unit can fix the issue or if full replacement is the only solution. The answer depends on the cause of the problem.

When Cleaning Might Help

  • Crystallization Build-Up
    DEF can crystallize over time, coating sensors and blocking accurate readings. Carefully cleaning off minor deposits may restore function temporarily.

  • Tank Debris or Contamination
    Dirt or particles inside the DEF tank can affect the sensors. Cleaning the tank and surrounding area may resolve certain issues.

  • Corroded Connectors
    Electrical connectors exposed to moisture may corrode. Cleaning them can restore communication between the head unit and ECM.

When Replacement Is Necessary

  • Sensor Damage
    If the quality, level, or temperature sensors are internally damaged, cleaning won’t restore accuracy.

  • Electronic Failures
    Circuit board or internal component failures cannot be repaired through cleaning.

  • Recurring Fault Codes
    If diagnostic trouble codes (DTCs) keep returning after cleaning attempts, the head unit likely needs replacement.

Cleaning a DEF head unit may help in cases of minor contamination or crystallization, but it’s rarely a permanent solution. Because the unit contains delicate sensors and electronics, many failures require replacement. If issues persist after cleaning, replacing the unit is the most reliable way to restore performance and avoid costly downtime.

The engine may derate power, emit emissions faults, or enter a safe mode until the unit is repaired or replaced.

It sends electrical or digital signals representing level, temperature, and quality for the ECM to adjust dosing.

It should be inspected at each scheduled service interval for sensor output consistency, sealing, and cleanliness.

Cold may slow sensor response or risk freezing, while high heat may cause drift or stress internal electronics.

Cummins DEF Head Units

PRODUCT VIDEOS