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Isuzu 4JJ1, 4HK1 DEF Head Unit 2016-2024: OEM 8-98273-439-1

ISUZU 4JJ1, 4HK1 DEF HEAD UNIT 2016-2024: OEM 8-98273-439-1

Shipping ICON

ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY

WARRANTY ICON

WARRANTY
1M MILES OR 1 YEAR

$1,250.00

AVAILABILITY IN STOCK
OEM NUMBER8-98273-439-1
PART TYPEDEF Head Unit
BRANDDuraWRX
ENGINE MAKEIsuzu
ENGINE TYPE4JJ1, 4HK1
YEAR2016-2024
PART NUMBERASPSZ2345-1
APPLICATION NOTESChevrolet LCF3500,4500,5500,
ADDITIONAL NOTES4.2 Gallon

PRODUCT DESCRIPTION

This is a New, DuraWRX DEF Head Unit, DuraWRX part number ASPSZ2345-1 ( OEM Part Number 8-98273-439-1 ).This part is primarily made for a Isuzu 4JJ1, 4HK1, production years 2016-2024, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here

Additional Notes: 4.2 Gallon

OEM NUMBERS

Primary OEM8-98273-439-1
Additional OEM8-98273-439-1

ADDITIONAL DETAILS

CONDITIONNew
UPC / Barcode00840490556164
WEIGHT5.00 LBS

SHIPPING OPTIONS

Ship Weight : 5.00 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.

"This Product Doesn't Have a Core"


Maintain reliable DEF system performance with the Isuzu 4JJ1, 4HK1 DEF Head Unit 2016–2024 (OEM 8-98273-439-1). Designed for Isuzu 4JJ1 and 4HK1 engines, this DEF head unit helps monitor and manage diesel exhaust fluid within the emissions system for dependable operation. Manufactured to meet OEM specifications, it provides precise fitment and reliable compatibility across the listed model years. Installing the correct DEF head unit helps support accurate system communication, efficient emissions control, and long-lasting reliability.

FITMENT CHART

YEARMAKEENGINE(S)
2016Isuzu 4JJ1 4HK1
2017Isuzu 4JJ1 4HK1
2018Isuzu 4JJ1 4HK1
2019Isuzu 4JJ1 4HK1
2020Isuzu 4JJ1 4HK1
2021Isuzu 4JJ1 4HK1
2022Isuzu 4JJ1 4HK1
2023Isuzu 4JJ1 4HK1
2024Isuzu 4JJ1 4HK1

PEOPLE ALSO ASKS | BLOG(S)

The Isuzu 4JJ1, 4HK1 DEF Head Unit 2016-2024: OEM 8-98273-439-1 is an essential component of the diesel exhaust fluid (DEF) system. It is designed to monitor and manage key DEF tank functions, helping the emissions system receive accurate information for proper operation. Choosing the correct OEM replacement helps maintain compatibility with Isuzu 4JJ1 and 4HK1 engines.

  • OEM 8-98273-439-1 fits Isuzu 4JJ1 and 4HK1 engines from 2016-2024
  • Designed to monitor important DEF system functions within the DEF tank
  • Supports communication between the DEF system and engine electronics
  • Manufactured to OEM specifications for precise fit and reliable installation
  • Durable construction designed for long-term use in commercial vehicles
  • Direct replacement for worn or malfunctioning DEF head units

The Isuzu 4JJ1, 4HK1 DEF Head Unit OEM 8-98273-439-1 is a dependable replacement component for maintaining proper DEF system operation and emissions system reliability. Tamerx Diesel Parts offers quality OEM-fit diesel emissions components trusted by truck owners and service professionals.

 

The DEF head unit is a critical component of the Diesel Exhaust Fluid (DEF) system, monitoring DEF level, temperature, and fluid quality. This information is sent to the engine control module to ensure the SCR system operates correctly. If the DEF head unit fails or provides inaccurate data, the vehicle may enter engine derate mode to maintain emissions compliance and protect the aftertreatment system.

  • Incorrect DEF level readings may cause the system to believe the tank is empty, even when it contains sufficient fluid.
  • Faulty temperature or quality sensor readings can prevent the SCR system from dosing DEF correctly.
  • Check engine lights or SCR warning messages often appear when the DEF head unit is malfunctioning.
  • Persistent fault codes related to the DEF system can trigger a gradual reduction in engine power.
  • In some applications, continued operation with unresolved DEF head unit faults may result in limited vehicle speed or engine derate.
  • Damaged wiring, poor electrical connections, or internal sensor failure can all contribute to incorrect DEF head unit operation.

A bad DEF head unit can lead to engine derate if the system is unable to verify proper DEF conditions. Prompt diagnosis and repair help restore accurate sensor readings, maintain SCR performance, and prevent unnecessary reductions in engine power.

 

Yes, contaminated or poor-quality DEF can affect the performance of the DEF system. Using DEF that meets ISO 22241 specifications helps protect the head unit.

Common causes include contamination, electrical problems, corrosion, and normal wear over time. Harsh operating conditions can also contribute to premature failure.

Yes, inaccurate or fluctuating DEF level readings are common signs of a failing head unit. Diagnostic testing can confirm whether the unit is functioning properly.

Technicians use diagnostic software to retrieve fault codes and monitor DEF system data. They also inspect electrical connectors and wiring for damage.