TICO Tractors Cummins ISB 6.7L DEF Head Unit
TICO TRACTORS CUMMINS ISB 6.7L 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 4310-18-19 ( OEM Part Number 621246-1 ). 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
Additional Notes: DEF Header, 40 MICRON, 18"
OEM NUMBERS
| Primary OEM | 621246-1 |
| Additional OEM | 621246-1 |
ADDITIONAL DETAILS
| CONDITION | Remanufactured |
| UPC / Barcode | 00840490540590 |
| 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.
The TICO Tractors Cummins ISB 6.7L DEF Head Unit (OEM 621246-1) is a critical component for managing Diesel Exhaust Fluid (DEF) levels and quality, ensuring that the engine complies with emissions standards. Built to OEM specifications, this DEF head unit guarantees reliable fitment and long-lasting performance in demanding diesel environments. Constructed from high-quality, corrosion- and chemical-resistant materials, it is designed to withstand the harsh conditions of commercial diesel operation. Each unit is thoroughly tested for sensor accuracy and electrical functionality, ensuring optimal performance over time. Ideal for professional technicians and fleet maintenance operations, this OEM DEF head unit supports efficient engine performance and reliable emissions control for Cummins ISB 6.7L engines in TICO Tractors.
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The DEF (Diesel Exhaust Fluid) Head Unit installed on a Cummins ISB 6.7 L engine serves as the pivotal interface between the DEF tank and the vehicle’s emissions (SCR) system. It monitors fluid levels, manages fluid flow, and communicates vital data to the engine’s control module to ensure clean, compliant operation.
How It Operates
- Fluid Level Sensing
- A built‑in level sensor measures the remaining amount of DEF in the tank and sends its signal to the engine control module (ECM) so the system knows when fluid is getting low.
- Temperature Monitoring
- A temperature sensor within the head unit keeps track of DEF fluid temperature. If the fluid gets too cold (freezing risk) or too hot (degradation risk), the system can respond accordingly.
- Fluid Routing (Header Function)
- The head unit includes internal passages: one draws DEF from the tank (pickup) toward the dosing/injection system, and often another returns unused fluid to the tank. This keeps the system primed and balanced.
- Filtration & Protection
- Before the fluid leaves the tank, it passes through a strainer inside the head unit. This blocks crystals or contaminants from damaging downstream components like the dosing injector.
- Data Communication
- The head unit transmits readings (level, temperature, and sometimes fluid condition) to the ECM, allowing accurate DEF dosing, system protection, diagnostics, and emission compliance.
By performing sensing, routing and communication in one compact assembly, the OEM 621246‑1 head unit ensures the DEF system in your TICO Tractors/Cummins ISB 6.7 L is working reliably, delivering proper fluid when needed, and keeping the SCR system functioning efficiently.
The DEF (Diesel Exhaust Fluid) Head Unit is a critical part of your vehicle’s emissions system. It monitors DEF level, temperature, and quality to ensure your vehicle runs efficiently and stays compliant with environmental standards. But what happens if the DEF Head Unit starts to fail? Can you continue driving, or is it better to address the issue right away?
Why You Shouldn’t Drive with a Bad DEF Head Unit
While your vehicle may still run with a malfunctioning DEF Head Unit, it is not safe or advisable to continue driving with this issue. Here's why:
- Emissions System Failure
- The DEF Head Unit ensures that the emissions system operates correctly. A bad unit will trigger faulty readings, which could cause the Exhaust Gas Recirculation (EGR) system or Diesel Particulate Filter (DPF) to underperform, leading to increased emissions and potential environmental violations.
- Check Engine Light and Warning Codes
- If the DEF Head Unit is malfunctioning, your dashboard will likely display a check engine light and trigger DEF system fault codes. These warnings indicate that the system is not functioning properly, and ignoring them can lead to further damage to other emissions components.
- Premature Derate Mode
- A faulty DEF Head Unit may cause your truck to enter derate mode. This severely limits vehicle performance, reducing speed to as low as 5 mph in some cases. Driving with a bad DEF Head Unit could result in being stranded or stuck in a location with limited ability to get your vehicle back on the road.
- Inaccurate DEF Level Readings
- If the DEF Head Unit isn’t working properly, it can provide inaccurate readings of the DEF tank level. This can lead to running out of DEF fluid unexpectedly, which can trigger additional engine restrictions or even cause a system shutdown, leaving you unable to drive.
What to Do If Your DEF Head Unit Is Failing
- Stop driving immediately
- if you notice warning lights or fault codes indicating DEF system issues.
- Check your DEF fluid
- and tank for contamination or issues before assuming the problem is with the Head Unit.
- Run a diagnostic scan
- to pinpoint the exact issue. If it’s the DEF Head Unit, replace it immediately — this part is not repairable and requires a full replacement.
- Consult a professional
- if you’re unsure about the problem. A technician can verify the fault and recommend next steps.
While it might be possible to drive with a bad DEF Head Unit for a short time, it’s not recommended. Continuing to operate your vehicle with a malfunctioning DEF system could result in further damage, poor performance, and costly repairs. Address the issue as soon as possible to keep your truck running efficiently and compliant with emissions regulations.
Exposure to DEF crystallization, vibration, dust, high ambient temperature and harsh field use typical of tractors.
It should be checked during major service intervals and anytime SCR or DEF system warnings or derates are recorded.
It restores reliable DEF system function, prevents derates or fault conditions, supports emissions performance and maximizes uptime.
Do not skip cleaning of fluid lines or harnesses, avoid loose or damaged connectors and ensure correct mounting to prevent leaks or sensor mis‑reads.
Cummins DEF Head Units
