Paccar / Cummins DEF Sensor : OEM ASP61DS21-FG
PACCAR / CUMMINS DEF SENSOR : OEM ASP61DS21-FG
ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY
WARRANTY
1M MILES OR 1 YEAR
PRODUCT DESCRIPTION
This is a Remanufactured, DuraWRX DEF Sensor, DuraWRX part number ASP61DS21-FG ( OEM Part Number ASP61DS21-FG ). This part is primarily made for a Paccar / Cummins , and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here
OEM NUMBERS
| Primary OEM | ASP61DS21-FG |
| Additional OEM | ASP61DS21-FG, Q21-6091, Q21-6127-002, Q21-6167-002, Q21-6167-002K1T, Q21-6167-002KIT, Q21-6170-002, Q21-6170-002K1T, Q216167-002 |
ADDITIONAL DETAILS
| CONDITION | New |
| UPC / Barcode | |
| WEIGHT | 3.00 LBS |
SHIPPING OPTIONS
Ship Weight : 3.00 LBS
UPS Ground, 2nd Day Air, Next Day Air
SHIPPING POLICY
Drive On Diesel 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 Drive On Diesel 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.
Drive On Diesel 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 Drive On Diesel, 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). Drive On Diesel 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 Drive On Diesel, 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"
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The DEF Sensor, part number ASP61DS21-FG, is a vital component used in Selective Catalytic Reduction (SCR) systems on a range of Paccar and Cummins platforms. This sensor monitors key Diesel Exhaust Fluid (DEF) parameters to help the vehicle's control system maintain compliance with emissions regulations.
Functions and Role in the Emissions System
The OEM ASP61DS21-FG is a multi-function CAN-based sensor designed to:
- Monitor DEF Level within the tank
- Measure DEF Temperature
- Evaluate DEF Quality (urea concentration)
These readings are continuously reported to the engine’s ECU to manage DEF dosing and ensure the SCR system operates correctly.
Key Features of OEM ASP61DS21-FG
- Integrated Sensor Assembly
- Combines level, temperature, and quality sensing in one compact unit
- Digital CAN-Bus Interface
- Enables accurate, real-time communication with engine controls
- Bayonet-Style Mounting
- Allows for quick and secure installation into the DEF tank
- Durable Construction
- Built to resist corrosion, temperature fluctuations, and DEF crystallization
- Direct Replacement Fit
- Compatible with several OEM part numbers, including Q21-6167-002 and Q21-6170-002 variants
Applications and Notes
This sensor is commonly found in Kenworth, Peterbilt, and other commercial vehicles equipped with Cummins or Paccar engines. It is critical for the sensor to function properly, as incorrect readings can trigger warning lights, fault codes, and possible derating of the engine.
To maintain emissions compliance and vehicle reliability:
- Use only clean, uncontaminated DEF
- Inspect wiring and connectors during installation
- Avoid over-torquing or misalignment when installing the sensor
A DEF (Diesel Exhaust Fluid) sensor is a critical component of a diesel engine’s emissions control system. It ensures the proper operation of the Selective Catalytic Reduction (SCR) system, which is responsible for reducing nitrogen oxide (NOx) emissions. Here's a breakdown of its main functions:
1. Monitoring DEF Level
The sensor continuously checks the amount of DEF in the tank. It sends this data to the vehicle’s Engine Control Module (ECM) to:
- Prevent DEF from running out
- Alert the driver when levels are low
- Avoid emissions system failures due to dry tanks
2. Measuring DEF Quality
Poor-quality or contaminated DEF (e.g., with water or other substances) can damage SCR components and reduce emission control effectiveness. The sensor measures the concentration of urea (typically 32.5%) to ensure it meets the required standard. If the quality is off:
- It may trigger warning lights or codes
- The engine may reduce allowable operating range due to EPA regulations
3. Monitoring DEF Temperature
Temperature monitoring ensures that:
- The fluid remains within the ideal range for injection
- The system can detect freezing conditions and initiate thawing if needed
- Overheated fluid, which could indicate a malfunction, is identified quickly
4. Communicating with the ECM
The DEF sensor transmits real-time data to the ECM, which uses it to adjust DEF injection rates. This helps maintain emissions compliance and system efficiency.
In short, the DEF sensor safeguards the SCR system by ensuring correct fluid levels, optimal temperature, and verified fluid quality. Failure of this sensor can lead to:
- Fault codes
- Derates (reduced engine function)
- Emissions violations
Routine inspections and using proper DEF fluid can help keep the system—and the sensor—in working condition.
You may need to replace the sensor if you see dashboard alerts, incorrect DEF readings, or system warnings.