2021-2024 Duramax L5P/LM2/LZ0 Diagnostic Plug
Fits: Duramax L5P (2017-Current 6.6L Duramax)
Diesel Dollars is Southern Diesel Supply's Loyalty Program. Purchasing with Us Earns you 1 Point for every 1 Dollar spent to use for future buys!
By ordering the 2021-2024 Duramax L5P/LM2/LZ0 Diagnostic Plug you will earn 120 DIESEL DOLLARS in your SDS Fuel Tank!
The USCAN4D diagnostic plug covers the 2024 6.6L Duramax L5P, the 2023-2024 3.0L LZ0 pickups and the 2021-2024 3.0L LM2 SUVs. It is made in America with an OEM connector and OEM pins, 100% sealed and covered by a lifetime warranty. Read the fitment note below: some truck-side harnesses have two indexing tabs that may need trimming.
Fitment
The maker's fitment list for part number USCAN4D:
- 2024 6.6L DURAMAX L5P: Chevrolet Silverado and GMC Sierra 2500HD-3500HD
- 2023-2024 3.0L DURAMAX LZ0 (Pick Up): Chevrolet Silverado and GMC Sierra 1500
- 2021-2024 3.0L DURAMAX LM2 (SUV)
Read that list closely. On the 6.6L side it is listed for 2024 only; 2017-2023 L5P trucks are not on the list. On the 3.0L side, the pickup years start at 2023 with the LZ0, while the SUV years run 2021-2024 with the LM2. 2025-2026 trucks take the newer USCAN5D version instead. Verify fitment by VIN or call the shop before you order.
Why this part
Because it is built with an OEM connector and OEM pins, this plug is designed to seat against the truck's own connector instead of relying on a generic housing. The one catch is the indexing tabs covered below: on some harnesses they stop the connectors from fully seating until they are trimmed. Once it is seated, the plug is 100% sealed against water and dirt. It is made in America, and the lifetime warranty stands behind it.
If you service more than one GM diesel from these years, the coverage is the draw: a 2024 heavy-duty L5P, a 2023-2024 Silverado or Sierra 1500 with the LZ0, and a 2021-2024 SUV with the LM2 all use this same part number. The LM2 and LZ0 are both 3.0L inline-six Duramax engines, a different family from the 6.6L in the HD trucks.
What you get
Feature list from the maker:
- Made in America
- Uses OEM Connector
- Uses OEM Pins
- 100% Sealed
- LIFETIME WARRANTY
Installation notes
Possible fitment modification required: some truck-side harnesses may have two indexing tabs that can prevent the connectors from fully seating. If this occurs, the tabs will need to be trimmed or ground down using a die grinder, cutoff wheel (Wiz Wheel), or similar tool. This modification is not required in every case, but it is a known possibility during installation. See the product photos for the indexing tab location.
Test-fit the plug before you cut anything, since the trim is not needed on every truck. If you do trim, remove only the two indexing tabs and clear the grinding dust out of the connector before you plug it in.
Frequently asked questions
Will this fit my 2020 or 2022 Silverado 2500HD?
Not according to the fitment list. On the 6.6L L5P it is listed for 2024 only, so call us with the VIN before ordering it for a 2017-2023 heavy-duty truck.
Do I have to grind the connector tabs?
Not always. Some truck-side harnesses have two indexing tabs that keep the connectors from fully seating. If yours does, trim or grind them down with a die grinder or cutoff wheel. If the plug seats fully on your truck, no modification is needed.
Which version do I need for a 2025 truck?
The 2025-2026 version, part number USCAN5D. This USCAN4D plug stops at the 2024 model year on every engine it lists.
Questions on fitment? Call the shop at the number in the header. We install everything we sell.
Diesel Dollars is Southern Diesel Supply's Loyalty Program. Purchasing with Us Earns you 1 Point for every 1 Dollar spent to use for future buys!
By ordering the 2021-2024 Duramax L5P/LM2/LZ0 Diagnostic Plug you will earn 120 DIESEL DOLLARS in your SDS Fuel Tank!