
Navistar/International IC Bus Cummins ISB 6.7L, B6.7 DEF Head Unit
NAVISTAR/INTERNATIONAL IC BUS 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 2321-18-2 ( OEM Part Number 4353004C92 ).This part is primarily made for a Cummins ISB 6.7L, B6.7, production years 2014-2024, 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 | 4353004C92 |
Additional OEM | 2512843C2, 2515988C3, 2523590C91, 4086806C91, 4087160C91, 4097724C91, 4097725C91, 4163693C91, 4163694C91, 4254215C91, 4353004C92 |
ADDITIONAL DETAILS
CONDITION | Remanufactured |
UPC / Barcode | 00840490541092 |
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 DEF system management is delivered by the Navistar/International IC Bus Cummins ISB 6.7L, B6.7 DEF Head Unit: OEM 4353004C92, a direct-fit replacement for compatible IC Bus vehicles. Manufactured to OEM standards, this unit tracks diesel exhaust fluid level, temperature, and quality to help maintain emissions compliance and consistent aftertreatment operation. Its durable construction withstands the demands of daily service, protecting both the exhaust system and overall engine efficiency. By choosing an OEM DEF head unit, you minimize compatibility risks and support dependable long-term performance. This component is a proven solution for keeping IC Bus Cummins-powered vehicles operating smoothly and without interruption.
FITMENT CHART
YEAR | MAKE | ENGINE(S) | ||||
---|---|---|---|---|---|---|
2014 | Cummins | ISB 6.7L | B6.7 | |||
2015 | Cummins | ISB 6.7L | B6.7 | |||
2016 | Cummins | ISB 6.7L | B6.7 | |||
2017 | Cummins | ISB 6.7L | B6.7 | |||
2018 | Cummins | ISB 6.7L | B6.7 | |||
2019 | Cummins | ISB 6.7L | B6.7 | |||
2020 | Cummins | ISB 6.7L | B6.7 | |||
2021 | Cummins | ISB 6.7L | B6.7 | |||
2022 | Cummins | ISB 6.7L | B6.7 | |||
2023 | Cummins | ISB 6.7L | B6.7 | |||
2024 | Cummins | ISB 6.7L | B6.7 |
PEOPLE ALSO ASKS | BLOG(S)
When it comes to modern diesel emissions systems, every component plays a vital role—and the DEF Head Unit OEM 4353004C92 is no exception. Found on Navistar/International IC Buses equipped with Cummins ISB 6.7L or B6.7 engines, this head unit is the central hub for monitoring and managing Diesel Exhaust Fluid (DEF). Whether you're operating a school bus, transit vehicle, or commercial fleet, this part ensures your emissions system runs clean, compliant, and without interruption.
What Does This DEF Head Unit Do?
Although it’s mounted on top of the DEF tank and appears simple from the outside, this unit handles a range of complex tasks that are critical for emissions control:
- Measures DEF Fluid Level
- Continuously monitors DEF quantity and sends data to the engine’s control module. This prevents unexpected shutdowns due to low fluid and triggers timely refill alerts.
- Monitors Fluid Temperature
- Tracks the DEF’s temperature to make sure it stays within operational range. Cold weather can cause DEF to freeze, and this unit helps the system respond accordingly.
- Filters the Fluid
- An internal screen or fine filter removes contaminants before DEF moves to sensitive downstream components like the dosing injector and SCR catalyst.
- Controls Fluid Flow (Suction and Return)
- Manages both the pickup and return paths of DEF, ensuring stable delivery pressure and avoiding air pockets or inconsistent dosing.
- Communicates with the Engine Control Module (ECM)
- Sends real-time sensor data to the ECM. If fluid levels are too low or temperatures too extreme, the system can warn the driver or adjust emissions behavior to prevent damage.
This head unit is more than just a sensor—it's a crucial link in your vehicle’s emissions chain. A malfunction can result in dashboard alerts, forced engine derate, or failure to meet emissions standards. On the other hand, a properly working 4353004C92 ensures your DEF system operates at peak efficiency, protecting both your engine and the environment.
In the fast-paced world of transportation, emissions compliance is non-negotiable. The DEF Head Unit OEM 4353004C92 quietly does its job behind the scenes, ensuring your IC Bus stays road-ready and environmentally sound. If you're replacing or maintaining your emissions system, this component is one you can’t afford to overlook. Stay ahead of issues by monitoring for common warning signs—and consider periodic inspection to ensure long-term reliability.
The DEF (Diesel Exhaust Fluid) head unit helps your vehicle meet emissions standards by reporting accurate data on fluid level, temperature, and quality. When it starts to fail, the system can behave unpredictably. But how do you know when it’s time to replace it instead of just cleaning or resetting?
Signs You May Need a New DEF Head Unit
If you’re experiencing any of the following issues, it may be time for a full replacement:
- Persistent dashboard alerts
- “Service DEF System” or “Poor DEF Quality” messages that won’t clear
- Unreliable fluid level readings
- DEF tank shows full when empty or vice versa, regardless of actual fluid
- Sudden engine derates
- Reduced speed or power even when DEF is clean and filled
- Inconsistent fluid use
- Sharp increase or drop in DEF usage without changes in driving habits
- Repeated fault codes
- Diagnostic tools keep showing sensor-related codes after fluid top-offs or resets
If standard maintenance doesn’t resolve these issues and wiring appears intact, it’s likely your DEF head unit is failing and should be replaced to restore system reliability.
The system may inject DEF incorrectly, leading to error codes and reduced performance.
It prevents unexpected derates that could interrupt critical passenger transport.
No, it must be replaced with the exact OEM part specified for IC Buses.
Yes, and doing so may cause incorrect readings and emissions system faults.