Skip to content
Warranty Shipping Contact Reviews
Trucktok 2011-2023 6.6L GM Chevy Duramax LML L5P Tuner Harness Plug Kit
Brand TruckTok

Trucktok 2011-2023 6.6L GM Chevy Duramax LML L5P Tuner Harness Plug Kit

SKU ER-0329-1
$129.99 - $139.99
$129.99
$129.99 - $139.99
$129.99

Free Shipping

Availability:
in stock, ready to be shipped
Availability:
in stock, ready to be shipped
%3Cp%3EEarn%20[points_amount]%20when%20you%20buy%20this%20item.%3C/p%3E
Request a quote

FITMENT

  • 2011–2023 6.6L Chevy Silverado & GMC Sierra Duramax LML L5P engines;
  • Note: The base kit does not include DEF tank plugs, Does not include shift on the fly plugs (Available Separately).

DESCRIPTION

Product Overview

  • Protect your truck's expensive factory wiring investment. When upgrading GM Duramax 6.6L LML L5P with custom tuning and off-road race configurations, several factory exhaust and engine sensors are disconnected, leaving vulnerable open plugs exposed to the elements.
  • The Tuner Harness Plug Kit provides a complete set of heavy-duty, weather-proof block-off plugs. They snap directly into your disconnected factory connectors, completely sealing out water, mud, salt, and debris to prevent short circuits and corrosion.
Key Features
  • Weatherproof Seal: Molded with high-grade automotive silicone/rubber seals to form an airtight barrier against high-pressure car washes, mud, and road salt.
  • Preserves Factory Wiring: Keeps factory harness pins clean, dry, and corrosion-free. If you ever need to return the truck back to its stock configuration, the original connectors will plug right back in flawlessly.
  • OEM-Style Snap Locking: Designed to the exact dimensions of GM’s factory plugs. They click securely into place and will not vibrate loose under heavy towing or rough terrain.

FAQ

Q: Why do I need a harness plug kit after tuning my GM Duramax truck?

A: When sensors are unplugged from the exhaust system, open chassis harness plugs are exposed to rain, mud, and road salt. These caps seal the electrical pin terminals completely dry, preventing short circuits and expensive wire harness replacement.

Q: Will using electrical tape work just as well as these weather-tight caps?

A: Electrical tape quickly melts under underbody heat, unravels in rainwater, and leaves sticky residue on pins. These hard-shell ABS caps provide permanent, heat-resistant, and reusable physical protection.

Q: Can I zip-tie the sealed wiring harnesses up along the frame rail after capping them?

A: Yes. Once sealed with our caps, zip-tying the loose wiring harnesses flat against the frame rail keeps them safely away from moving suspension components and exhaust heat.

Q: Will installing these plugs prevent corrosion-induced short circuits that trigger false ECM error codes?

A: Yes. By completely isolating the open copper pin terminals from road salt and ambient moisture, you prevent parasitic battery drain, unexpected CAN-bus network errors, and terminal pin oxidation.

  • 5 stars: 1 (17%)
  • 4 stars: 2 (33%)
  • 3 stars: 3 (50%)
  • 2 stars: 0 (0%)
  • 1 star: 0 (0%)
This product has no reviews of its own. The merchant grouped it with related products, so the reviews shown are from across that group.
H
Hank Boudreaux
2022 L5P — ghost codes gone after plugs installed

2022 Silverado 2500. After my delete tune was loaded I still had P20EE and P249D pending codes. The tuner said those are rationality codes from the NOx sensors seeing an open circuit. Installed this plug kit, cleared the codes, and they never came back. The plugs have the right resistance to simulate a sensor still being connected. 10K miles since and the truck runs clean with no CEL.

B
Beau Fontenot
2020 L5P — 9th injector and DEF line heater covered too

2020 GMC Denali HD. The 2020+ L5P adds a 9th injector for DPF regeneration and a heated DEF line. This kit has plugs for both. The 9th injector connector is a different style than the other injectors and the kit has the correct plug. Also has the DEF tank heater and pump connectors. Installed in about 20 minutes — all under-truck connectors are reachable without dropping the tank.

W
Waylon Hightower
2018 L5P — more connectors than LML, all covered

2018 Silverado 3500. The L5P has a more complex emissions system than the LML — more NOx sensors, a different EGR cooler bypass setup, and additional pressure sensors. I was worried a generic kit would miss some, but this TruckTok L5P-specific kit had plugs for everything. The connectors are all OEM-style with locking tabs and the grommets seal tightly. No open connectors, no water intrusion.

D
Dusty Prather
EZ Lynk tuner confirmed — no open-circuit codes with these

2016 Silverado 2500. Had my tuner remote in after the delete and he said the harness was showing several open-circuit codes that the tune would need to mask. Added this plug kit, he re-checked, and the open circuits were gone because the plugs have the correct termination. That means fewer custom tune parameters and a cleaner flash. The plugs are cheap insurance for a clean tune.

C
Colt Boudreaux
Kept the LML factory harness reversible for resale

2015 GMC Denali HD. I wanted to keep the factory harness intact in case I sell the truck one day and the buyer needs it emissions-compliant. This plug kit caps every emissions connector without cutting anything. The DEF tank plugs are especially important because those connectors sit under the truck in salt and slush. The silicone boots are thick and sealed tight. 50K miles later the connectors underneath look brand new.

R
Rusty Weatherby
2013 LML — every open connector capped after DPF+EGR delete

2013 Silverado 3500. LML delete means you have open connectors for the EGR valve, EGR cooler bypass, throttle valve, DPF pressure sensor, DEF injector, DEF tank heater, and both NOx sensors. This TruckTok plug kit covers all of them. Each plug is weather-sealed with a silicone boot and clicks into the factory connector like OEM. No more moisture in the connectors, no more intermittent circuit codes. The kit is labeled so you know which plug goes where.