GM VIN Decoder — Free Character-by-Character Breakdown for Every General Motors Vehicle.
Every General Motors vehicle — every Chevrolet, GMC, Cadillac, and Buick sold today, plus the historic Oldsmobile, Pontiac, Saturn, and Hummer nameplates — carries a 17-character VIN that starts with G in position 2 to identify the umbrella manufacturer. This GM VIN decoder splits the string into 12 fields you can actually read: the WMI (1G1, 1G2, 1G6, 1GC, 1GT, and more), the model line, the engine code at position 8, the model year, and the plant. Paste any GM VIN below and we'll decode it in seconds. Free, no sign-up.
Free GM VIN Decoder — Break Down Any General Motors VIN
Enter a GM VIN (Chevrolet, GMC, Cadillac, or Buick) and we'll return WMI, division, engine code, model year, plant, and serial — plus open recalls from the live NHTSA feed.
Free · No sign-up · Instant result
Quick Answer
- How do I decode a GM VIN?
- Read the 17-character VIN from the windshield or door jamb and paste it into CarCheckerVIN's free GM VIN decoder. It breaks out the WMI, division (Chevrolet, GMC, Cadillac, Buick), engine code at position 8, model year, plant, and serial in seconds.
- What are the main GM WMIs?
- 1G1 and 1G2 = Chevrolet US passenger. 1G6 = Cadillac US. 1GC = Chevrolet US truck. 1GT = GMC US truck. 1G4 = Buick US. Historic: 1G3 = Oldsmobile (discontinued 2004), 1G8 = Saturn (discontinued 2010).
- How does GM encode the engine at position 8?
- Position 8 on GM VINs identifies the engine. Common codes: T = LT1 6.2L V8 (Corvette), Y = LT2 6.2L V8, W = 6.6L Duramax diesel L5P, F = 3.6L LFY V6, K = 5.3L LM7 V8, J = 6.2L L87 V8 (Silverado/Sierra). The decoder handles every GM engine code across all divisions.
What a GM VIN Decodes
A single GM VIN carries enough encoded data to reconstruct the vehicle from the build sheet: which division built it, where the plant is, what LS or Duramax engine came off the line with it, and which model line and trim it belongs to. The decoder pulls the six most-useful fields from the 17 characters.
Division (position 3)
Position 3 identifies the GM division. 1 = Chevrolet passenger (Malibu, Camaro, Corvette). 4 = Buick (Enclave, Encore). 6 = Cadillac (CT4, CT5, Escalade). C = Chevrolet truck (Silverado, Tahoe, Suburban, Colorado). T = GMC truck (Sierra, Yukon, Canyon). 3 = Oldsmobile (historic, discontinued 2004). 8 = Saturn (historic, discontinued 2010). 2 = Pontiac (historic, discontinued 2010). This is the single most useful field for identifying the brand under the GM umbrella.
Model line (position 6)
Position 6 identifies the specific model line within the division. Silverado 1500 vs Silverado HD, Tahoe vs Suburban, CT4 vs CT5, Malibu vs Camaro — each has a distinct character. The decoder returns the model name in plain English.
Engine code (position 8)
The 8th character encodes the engine. GM uses a shared coding system across divisions where possible: T = LT1 6.2L V8 (Corvette C7), Y = LT2 6.2L V8 (Corvette C8), J = L87 6.2L V8 (Silverado/Sierra/Escalade), K = LM7 or L83 5.3L V8, W = L5P 6.6L Duramax diesel V8, F = 3.6L LFY V6, 1 = 2.7L Turbomax I4 (L3B on Silverado). Decoding position 8 confirms whether the seller's engine description matches the factory build.
Check digit (position 9)
The 9th character is a mathematically-calculated check digit. It validates the other 16 characters. A GM VIN with a bad check digit is a red flag for tampering — especially concerning on Corvette Z06 and Cadillac Escalade purchases where badge and trim value can create incentives for identity swap.
Model year (position 10)
The 10th character encodes the model year: F=2015 through T=2026. GM uses the same model-year chart as every other US manufacturer. Position 10 combined with position 8 tells you the engine generation — for example, a T at position 8 with model year 2018 (position 10 = J) means LT1 6.2L V8 in a C7 Corvette Z06; the same T with model year 2024 (position 10 = R) means something different in a different chassis.
Plant + serial (positions 11-17)
Position 11 identifies the plant. F = Flint (Silverado HD). K = Fort Wayne (Silverado 1500). N = Arlington, TX (Escalade, Suburban, Tahoe). C = Detroit-Hamtramck / Factory Zero (Hummer EV, Silverado EV, Escalade IQ). G = Ramos Arizpe, Mexico (some Silverado/Sierra crew cabs, Blazer). Positions 12-17 form the six-digit serial.
GM VIN Position-by-Position Breakdown
The 17 characters in a GM VIN follow the ISO 3779 international standard. GM uses specific codes at each position that apply across all four current divisions (Chevrolet, GMC, Cadillac, Buick) and the historic ones (Oldsmobile, Pontiac, Saturn, Hummer). The 3rd character — the division code — is the most important field for identifying which nameplate you are looking at. Here is the position-by-position breakdown, plus a mini-table of model-year codes from 2015 through 2026.
| Position | Generic meaning | GM-specific example |
|---|---|---|
| 1 | Country of origin | 1 = US, 2 = Canada, 3 = Mexico, K = South Korea (Sonic/Trax) |
| 2 | Manufacturer | G = General Motors |
| 3 | Division / vehicle type | 1 = Chevrolet passenger, 2 = Pontiac (historic), 3 = Oldsmobile (historic), 4 = Buick, 6 = Cadillac, 8 = Saturn (historic), C = Chevrolet truck, T = GMC truck |
| 4-5 | Restraint / body / GVWR | GVWR class + body style |
| 6 | Model line | Silverado/Sierra 1500, Tahoe/Yukon, Suburban/Yukon XL, Escalade, Malibu, Cruze, CT4/CT5 |
| 7 | Body type | Regular cab, crew cab, coupe, sedan, SUV 4-door |
| 8 | Engine code | T = LT1 6.2L V8, Y = LT2 6.2L V8, J = L87 6.2L, K = LM7/L83 5.3L V8, W = L5P 6.6L Duramax, F = 3.6L LFY V6, 1 = 2.7L Turbo I4 (L3B) |
| 9 | Check digit | Calculated from other 16 characters |
| 10 | Model year | F=2015 → T=2026 (see mini-table) |
| 11 | Assembly plant | F = Flint (Silverado HD), K = Fort Wayne (Silverado 1500), G = Ramos Arizpe MX, C = Detroit-Hamtramck / Factory Zero (EVs), N = Arlington TX (Escalade/Suburban) |
| 12-17 | Sequential serial | Six-digit production number |
GM model-year codes (position 10)
FGHJKLMNPRSTPosition 10 encodes model year. Letters I, O, Q, U, Y, Z are never used. Cross-check with position 8 to disambiguate reused engine codes between generations.
Where to Find Your GM VIN
GM prints the VIN in at least five places on every modern Chevrolet, GMC, Cadillac, and Buick. On Silverado, Sierra, and Escalade the frame-rail stamp is the tamper-resistant location.
The fastest place to find a GM VIN is the lower driver-side corner of the windshield — look through the glass from outside. The driver-side door jamb sticker is the second-easiest place; GM includes it as required by federal law, and it also lists the tire pressure spec and the manufacture date. The title, insurance ID card, and state registration all print the VIN.
On Silverado, Sierra, Tahoe, Yukon, Suburban, and Escalade full-size trucks and SUVs, the driver-side frame-rail VIN stamp is the authoritative source — GM presses the VIN directly into the steel of the frame at build time. On a used truck, cross-check the door plate against the frame stamp; a mismatch is a strong signal that the body has been swapped onto a different frame. On Corvette, look also for the VIN plate visible through the windshield on the passenger side.
Five places the GM VIN lives
- Lower driver-side windshield (visible from outside)
- Driver-side door jamb sticker (also lists tire pressure)
- Driver-side frame rail stamp (Silverado / Sierra / full-size SUV)
- GM title document
- Insurance ID card + state registration
Found it? Drop the 17-character GM VIN into the form above and decode it in seconds.
Decode Your GM VIN Right Now
Got a Chevrolet, GMC, Cadillac, or Buick VIN to check? Run it through the decoder for a full character-by-character breakdown. Free, in seconds.
Common GM Issues Revealed by VIN
GM has issued significant recall campaigns across all four divisions. A decoded VIN tells you whether that specific vehicle is affected. The decoder is especially useful for the shared-platform vehicles where the same recall covers Chevrolet Silverado, GMC Sierra, and Cadillac Escalade under one campaign.
L87 6.2L V8 connecting rod / bearing
GM issued a large recall on 2019-2024 Chevrolet Silverado, Silverado HD, Suburban, Tahoe, GMC Sierra, Yukon, and Cadillac Escalade with the 6.2L L87 V8 for connecting-rod and main-bearing debris. The decoder confirms the J engine code at position 8 and the model year, then cross-references the NHTSA feed to show whether the engine service has been completed on that VIN.
6.6L Duramax fuel system
Certain 2020-2023 Silverado HD and Sierra HD with the 6.6L L5P Duramax diesel have been recalled for high-pressure fuel-pump contamination that can cause engine failure. The decoder confirms the W engine code and the HD chassis context, and the recall check confirms whether the fuel-system service has been performed on that VIN.
Chevrolet Bolt EV battery / LG cells
The Chevrolet Bolt EV received a full battery-module replacement recall for LG-made cells with potential thermal runaway. The decoder confirms the Bolt platform (position 4-6 combination) and pulls the model year (2017-2022 range affected), and the recall check confirms whether the battery replacement has been performed on that VIN.
Buying a used GM vehicle? Pair this GM VIN decoder with a focused recall check and an accident history check — GM's high-volume trucks and SUVs accumulate a lot of records.
GM VIN Decoder vs OnStar Owner Portal
GM operates myChevrolet, myGMC, myCadillac, and myBuick apps plus the OnStar owner portal where registered owners can look up basic model info and recall status by VIN. Those tools are useful if you already own the vehicle, but they require an OnStar / GM account and do not surface title brands, salvage records, or the position-by-position decoding this tool provides.
A free GM VIN decoder gives you the character-by-character breakdown that any buyer can read on their own — division, model line, engine code, model year, and plant. For used GM buyers looking at Silverado, Sierra, Escalade, Suburban, Tahoe, Corvette, or any Chevy/GMC/Cadillac/Buick, the decoder is the practical entry point. Follow it with a full VIN history report to see title chain, odometer snapshots, and any total-loss claims.
The right call depends on what you are buying. For a used Silverado 1500 or Tahoe, the free decoder catches the L87 recall context in seconds. For a used Corvette Z06 or Escalade-V, run the decoder first — then order a full history report before the price crosses the six-figure line.
GM VIN decoder checklist
- Confirm the VIN is exactly 17 characters (no I, O, Q)
- Read position 3 to identify the division (Chevy/GMC/Cadillac/Buick)
- Verify the WMI matches (1G1, 1G2, 1G4, 1G6, 1GC, 1GT)
- Read the model line off position 6
- Check the engine code at position 8 (T, Y, J, K, W, F, 1)
- Read the model year off position 10 (see the mini-table)
- Cross-check frame-rail stamp against door plate on Silverado/Sierra
Decode the VIN first — paste the GM VIN here:
Related VIN Tools for GM Owners
The GM VIN decoder is the starting point. These focused tools dig into specific records when something looks off — or when you want a complete picture before you buy.
Always check the VIN before you buy
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GM VIN Decoder — Frequently Asked Questions
The questions Chevrolet, GMC, Cadillac, and Buick owners ask most when they want to decode a GM VIN.
How do I decode a GM VIN?+
To decode a GM VIN, find the 17-character VIN on the lower driver-side corner of the windshield, the driver-side door jamb sticker, the title, or the insurance card. Enter it into the free GM VIN decoder on this page. The tool validates that the VIN is exactly 17 characters, calculates the check digit, and returns 12 decoded fields: the WMI (positions 1-3), body/GVWR (4-5), model line (6), body type (7), engine code (8), check digit (9), model year (10), plant (11), and production serial (12-17). The tool handles all four current GM divisions — Chevrolet, GMC, Cadillac, and Buick — plus the historic Oldsmobile, Pontiac, Saturn, and Hummer nameplates. Free, no sign-up.
What is the difference between GM VIN and Chevrolet VIN?+
There is no functional difference — a Chevrolet VIN is a GM VIN. General Motors is the umbrella parent company, and all four current divisions (Chevrolet, GMC, Cadillac, Buick) plus the historic ones (Oldsmobile, Pontiac, Saturn, Hummer) use the same 17-character VIN structure with G as the manufacturer code at position 2. Position 3 differentiates the division: 1 for Chevrolet passenger, 4 for Buick, 6 for Cadillac, C for Chevrolet truck, T for GMC truck, and so on. So 'GM VIN decoder' and 'Chevrolet VIN decoder' return the same fields — but a GM decoder handles all four brands, while a Chevrolet-only decoder would skip Buick and Cadillac codes.
How do I read the engine from a GM VIN?+
Position 8 of a GM VIN carries the engine code. Common GM engine codes across the current lineup: T = LT1 6.2L V8 (C7 Corvette Stingray, some Camaro SS). Y = LT2 6.2L V8 (C8 Corvette Stingray). J = L87 6.2L V8 (Silverado 1500 / Sierra 1500 / Tahoe / Yukon / Suburban / Escalade). K = LM7 or L83 5.3L V8 (older Silverado / Tahoe / Suburban). W = L5P 6.6L Duramax diesel V8 (Silverado HD / Sierra HD). F = 3.6L LFY V6 (Traverse / Acadia / XT5). 1 = 2.7L Turbomax I4 (L3B, base Silverado / Sierra 1500). The decoder returns the exact engine designation and cross-references position 10 (model year) to distinguish between generations of the same code letter.
What are the main GM WMI codes?+
The World Manufacturer Identifier (positions 1-3) for GM breaks down as: 1G1 = Chevrolet US-built passenger car. 1G2 = Chevrolet US-built passenger (secondary block, historically Pontiac shared). 1G3 = Oldsmobile US-built passenger (historic, division discontinued 2004). 1G4 = Buick US-built passenger. 1G6 = Cadillac US-built passenger. 1G8 = Saturn US-built (historic, discontinued 2010). 1GC = Chevrolet US-built truck (Silverado, Colorado, Traverse). 1GT = GMC US-built truck (Sierra, Canyon, Acadia). Canadian-built GM vehicles use 2G at the WMI start; Mexican-built use 3G. Korean-built (Sonic, Trax historic) used KL. The first character always identifies country of origin — 1 for US, 2 for Canada, 3 for Mexico.
How do I identify GM division from the VIN?+
Position 3 of a GM VIN identifies the division. 1 = Chevrolet passenger cars. 2 = Pontiac (discontinued 2010 — you will only see this on used cars now). 3 = Oldsmobile (discontinued 2004). 4 = Buick. 6 = Cadillac. 8 = Saturn (discontinued 2010). C = Chevrolet trucks. T = GMC trucks. So a VIN starting 1G1 tells you Chevrolet passenger car US-built, and 1GT tells you GMC truck US-built. This is the fastest way to tell a Chevrolet Silverado apart from a GMC Sierra without opening the door — the trucks are mechanically twins but their WMI positions 3 differ.
Where is the VIN located on a GM vehicle?+
GM prints the VIN in at least five places on every modern Chevrolet, GMC, Cadillac, and Buick. The fastest is the lower driver-side corner of the windshield, visible by looking through the glass from outside the car. The driver-side door jamb sticker is the second-easiest place — GM includes it as required by federal law, and it also lists the tire pressure spec and the manufacture date. On Silverado, Sierra, Tahoe, Yukon, Suburban, and Escalade the driver-side frame-rail VIN stamp is the authoritative source (physically pressed into the steel). The VIN also appears on the title document, the insurance ID card, and the state registration document. On a used Silverado or Sierra, always cross-check the door plate against the frame-rail stamp before you buy.
Which GM vehicles does the decoder cover?+
The GM VIN decoder handles every 17-character VIN sold under the General Motors umbrella since 1981. Current divisions: Chevrolet (Silverado, Silverado HD, Colorado, Malibu, Camaro, Corvette C7/C8/C8 Z06/C8 ZR1, Blazer, Traverse, Equinox, Tahoe, Suburban, Trax, Trailblazer, Bolt EV/EUV, Silverado EV). GMC (Sierra 1500, Sierra HD, Canyon, Terrain, Acadia, Yukon, Yukon XL, Hummer EV, Hummer EV SUV). Cadillac (CT4, CT5, CT4-V, CT5-V, CT5-V Blackwing, XT4, XT5, XT6, Escalade, Escalade-V, Escalade IQ, Lyriq, Optiq). Buick (Encore GX, Envista, Envision, Enclave). Historic: Oldsmobile, Pontiac, Saturn, Hummer H1/H2/H3. For very early GMs (pre-1981) that predate the 17-character standard, the decoder returns a chassis-number guidance page.
Ready to Decode a GM VIN?
Enter any 17-character GM VIN — Chevrolet, GMC, Cadillac, or Buick — for a free position-by-position breakdown. No account required.
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