GM Gen V EcoTec3 5.3L V8 L83 & L8B: Specs, Engine Codes, Controllers & Maintenance
Engine Information · GM · Small-block · Gen V · K2XX
Gen V EcoTec3 5.3L V8 L83 & L8B
The L83 brings direct injection, cam phasing and AFM to the familiar 5.3L V8. L8B adds eAssist mild-hybrid equipment, giving it separate electrical and control-system requirements even though the quoted engine output is similar.

Engine construction
| Specification | Details |
|---|---|
| Capacity / layout | 5.3L · 90° V8 |
| Construction | Aluminum block and heads |
| Valve gear | OHV · 2 valves per cylinder · variable cam timing |
| Fuel / induction | Direct injection · naturally aspirated |
| Valves / cylinders | 16 valves · AFM |
| L8B equipment | eAssist motor-generator and lithium-ion battery |
Codes & output
| RPO / version | Power / torque | Key difference |
|---|---|---|
| L83 | 355 hp / 383 lb-ft | Gasoline rating; approved E85 applications can differ |
| L8B | 355 hp / 383 lb-ft | Engine rating; eAssist assistance is separate |
SAE horsepower; torque in lb-ft. Ratings are for the stated application and fuel, rather than every vehicle with this RPO.
Vehicles & model years
| Brand | Model | Model years | Platform / chassis | Engine RPO |
|---|---|---|---|---|
| GMC / Chevrolet | Sierra / Silverado 1500 | 2014–2018; selected 2019 Limited / LD | K2XX | L83 |
| GMC / Chevrolet | Yukon / Tahoe / Suburban | 2015–2020 | K2XX | L83 |
| GMC / Chevrolet | Sierra / Silverado eAssist | 2016–2018 | K2XX | L8B |
U.S. and Canadian applications within the 2005–2026 matrix scope. Engine availability depends on trim, build date and emissions certification.
Engine controllers
| Application / revision | ECM or PCM | Identification & function |
|---|---|---|
| L83 / L8B engine management | GM E92 / E92A-family ECM | Direct injection, fuel pressure, AFM, VVT and electronic throttle; hardware revision must be read |
| L8B eAssist | ECM plus hybrid / battery controls | Motor-generator torque, restart and battery management require the eAssist vehicle calibration |
Identify the module from its service number, operating-system ID and VIN. The ECM/PCM and transmission controller have separate calibrations on many applications; a matching RPO alone does not make a replacement module plug-and-play.
Common issues & maintenance
- AFM lifter / valvetrain faultsA new tick with a persistent cylinder misfire can indicate a collapsed lifter, damaged pushrod or cam wear. Check compression and valve movement; not every misfire is a lifter.
- Direct-injection faultsInjector leakage or incorrect delivery can cause rough starts, misfires or fuel dilution. Fuel-pressure and cylinder tests identify the fault.
- Oil-pressure faultsOil-pump control and sensor faults need mechanical pressure verification and scan data. Use the correct filter and oil before condemning the pump.
Keep it healthy. Use the prescribed dexos oil and filter, keep oil at the correct level and respond quickly to valvetrain noise. L8B also needs its eAssist cooling and electrical systems maintained; low voltage or hybrid faults can affect restart and drivability.
References & technical sources
| Source | Reference |
|---|---|
| GM applications & RPO diagnostic matrices | View source |
| EFILive GM gasoline controller families | View source |
| GMC 2017 Sierra factory brochure | View source |
| GM 19-NA-219: misfire diagnosis | View source |
| GM oil-pump diagnosis PIP5407B | View source |
