Factory build sheet

2021 GMC Sierra Fleet/Base

Build 1GD59SEY-M · 6.6L 8cyl · Four-wheel drive · Incomplete - Chassis CAB (Double CAB)

VIN positions 1 through 8 read 1GD59SEY and position 10 reads M. Those nine characters define this build. Position 9 and positions 11 through 17 differ on every car.

Every Sierra whose VIN starts 1GD59SEY and carries M in position 10 left the plant with the same engine, transmission, drivetrain and equipment listed below. We know of 16 of them.

  • Decoded Sep 9, 2026
  • 16 known VINs
  • 1 listed for sale now

Factory specification

As filed by GMC with NHTSA for this build. Fields the filing does not record are left out entirely — a missing row means no recorded value, not a missing feature.

Engine

Displacement
6.6 L
Cylinders
8
Configuration
V-Shaped
Engine model
L5P - DI, DURAMAX, GEN 5 VAR. 1
Turbocharged
Yes
Fuel type
Diesel

Drivetrain

Drive type
Four-wheel drive
Brake system
Hydraulic

Body & chassis

Body class
Incomplete - Chassis Cab (Double Cab)
NHTSA body type
INCOMPLETE VEHICLE
Cab type
Extra/Super/Quad/Double/King/Extended
Series
3500
Manufacturer
GENERAL MOTORS LLC

Weight rating

GVWR class
Class 3
GVWR
10,001–14,000 lb

Gross vehicle weight rating is the loaded ceiling set by the manufacturer, not the car's own weight.

How this VIN pattern is read

A 17-character VIN carries two kinds of information: what was built, and which one it is. This page is the first kind — the nine highlighted positions.

Positions Characters What they encode
1–3 1GD GENERAL MOTORS LLC · World manufacturer identifier
4–8 59SEY Model, body style, engine and restraint system
9 × Check digit — computed per vehicle, not part of the build
10 M Model year — 2021
11 × Assembly plant
12–17 ×××××× Production sequence number, unique to each vehicle

16 vehicles carry this build

Every VIN we have decoded to 1GD59SEY-M shares the specification above.

  • 16 Known VINs
  • 1 Listed for sale now

Keep going

Where this data comes from

Specification fields are decoded from the manufacturer's filings in the NHTSA vPIC database, keyed on VIN positions 1–8 and 10. We publish the filed values as they stand and leave out anything the filing does not record.

Vehicle counts come from the 16 VINs of this build we have seen in dealer inventory. They are a sample of the road population, not a production figure.