
Navistar/International IC Bus International N9, N10, N13, DT DEF Head Unit
NAVISTAR/INTERNATIONAL IC BUS INTERNATIONAL N9, N10, N13, DT 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 2321-18-3 ( OEM Part Number 2523590C91 ).This part is primarily made for a International N9, N10, N13, DT, production years 2011-2016, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here
Additional Notes: QLS DEF Header, 449mm
OEM NUMBERS
Primary OEM | 2523590C91 |
Additional OEM | 2512843C2, 2515988C3, 2523590C91, 4086806C91, 4087160C91, 4097724C91, 4097725C91, 4163693C91, 4163694C91, 4254215C91, 4353004C92 |
ADDITIONAL DETAILS
CONDITION | Remanufactured |
UPC / Barcode | 00840490541122 |
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 reliability, the Navistar/International IC Bus DEF Head Unit OEM 2523590C91 fits International N9, N10, N13, and DT engines from 2011 to 2016. This genuine OEM part plays a vital role in the Diesel Exhaust Fluid system, supporting emissions compliance and dependable operation. Built to match original factory specifications, it ensures precise installation and consistent functionality. Its strong construction is well-suited to the daily demands of commercial trucks and buses, offering long-lasting service you can trust. For fleets and operators needing a dependable replacement, this DEF head unit provides the quality and assurance expected from an OEM component.
FITMENT CHART
YEAR | MAKE | ENGINE(S) | ||||
---|---|---|---|---|---|---|
2011 | International | N9 | N10 | N13 | DT | |
2012 | International | N9 | N10 | N13 | DT | |
2013 | International | N9 | N10 | N13 | DT | |
2014 | International | N9 | N10 | N13 | DT | |
2015 | International | N9 | N10 | N13 | DT | |
2016 | International | N9 | N10 | N13 | DT |
PEOPLE ALSO ASKS | BLOG(S)
Between 2011 and 2016, Navistar and International IC Bus models equipped with the N9, N10, N13, and DT engines relied on the DEF Head Unit OEM 2523590C91 as a vital part of their emissions control system. This unit is often referred to as a DEF head or sensor head, and it combines several sensors and features into a single assembly.
Main Components
- DEF Tank Level Sensor (DEFTL)
- Measures how much Diesel Exhaust Fluid is stored in the tank and sends signals when the fluid reaches critical levels.
- DEF Tank Temperature Sensors
- Typically includes two sensors:
- DEFTT1: Primary sensor monitoring fluid temperature.
- DEFTT2: Secondary sensor or backup reading, often integrated with the quality sensor.
- Typically includes two sensors:
- Urea Quality Sensor (UQS)
- Monitors the chemical composition of the DEF to ensure it meets strict standards. It helps detect contamination or off-spec fluid.
- DEF Tank Heater
- Uses engine coolant circulation to prevent DEF from freezing in cold temperatures, keeping the system ready to operate in all climates.
By combining level detection, temperature monitoring, quality assurance, and heating in one compact unit, the DEF Head Unit OEM 2523590C91 ensures emissions compliance and reliable operation of the entire system.
A faulty DEF (Diesel Exhaust Fluid) head unit can leave drivers wondering if they can still operate their vehicle safely. While it may be possible to drive for a short period, it’s not recommended as a long-term solution.
What Happens When the DEF Head Unit Fails?
The head unit monitors fluid quality, level, and temperature. When it malfunctions, the system cannot accurately report data to the engine control module. This leads to warnings and eventually strict limitations.
Key Issues You’ll Face:
- Dashboard alerts
- notifying you of a DEF system fault
- Countdown to limited operation
- once the fault is detected
- Severely restricted driving range
- if the issue is ignored
- Risk of derate mode,
- which can reduce speed to as little as 5 mph
Continuing to drive with a bad DEF head unit is risky. While your truck may run temporarily, regulations require the emissions system to function properly. Ignoring the fault can quickly lead to costly downtime.
If your DEF head unit fails, schedule service as soon as possible. Acting quickly prevents being stranded with a truck limited to low speed, saving both time and frustration.
A faulty unit can cause error codes and restrict engine operation until replaced.
Yes, a failing DEF head unit may trigger derate conditions until it is replaced.
Yes, installing the wrong unit can cause incorrect readings and potential system faults.
They confirm it by reading fault codes and testing DEF tank sensor signals.