← All owner tools · Decode your own SPID label with the GM RPO decoder
| Code | Meaning | Years | Sourcing |
|---|---|---|---|
| 001 | P RAT, M RATIO, 3.70 | 1991 | GM sourced |
| 001 | Rat, M Ratio, 3.70 | 1991 | GM dated |
| 002 | P RAT, M RATIO, 4.11 (4 1/9) | 1991 | GM sourced |
| 002 | Rat, M Ratio, 4.11 (4 1/9) | 1991 | GM dated |
| 003 | Rat, M Ratio, 4.33 | 1991 | GM dated |
| 003 | P RAT, M RATIO, 4.33 | 1991 | GM sourced |
| 004 | Rat, M Ratio, 4.78 | 1994 | GM dated |
| 004 | P RAT, M RATIO, 4.78 | 1994 | GM sourced |
| 005 | Rat, M Ratio, 4.56 (4 5/9) | 1991 | GM dated |
| 005 | P RAT, M RATIO, 4.56 (4 5/9) | 1991 | GM sourced |
| 006 | Rat, M Ratio, 4.63 (4 5/8) | 1996 | GM dated |
| 006 | P RAT, M RATIO, 4.63 (4 5/8) | 1996 | GM sourced |
| 007 | Rat, M Ratio, 3.07 | 1997 | GM dated |
| 007 | P RAT, M RATIO, 3.07 | 1997 | GM sourced |
| 008 | Rat, M Ratio, 4.88 | 1996 | GM dated |
| 008 | P RAT, M RATIO, 4.88 | 1996 | GM sourced |
| 009 | Rat, M Ratio, 5.29 | 1991 | GM dated |
| 009 | P RAT, M RATIO, 5.29 | 1991 | GM sourced |
| 00A | Spare wheel upgrade Chevrolet Silverado 1500 | 2022–2023 | GM sourced |
| 00A | Wheel Spare 17 X 8.0, J, Steel, Design 2 | — | Reference |
| 00D | Not Equipped with Climate Control Knob Digital Temperature Display Chevrolet Silverado 1500 | 2022 | Provisional |
| 00G | Not Equipped with Heated Steering Wheel, see dealer for details Chevrolet Silverado 1500 | 2022–2023 | Provisional |
| 00L | Ccl, R Secondary Color, Exterior, Prime | 1989 | GM dated |
| 00L | P CCL, R SECONDARY COLOR, EXTERIOR, PRIME | 1989 | GM sourced |
| 00L | Exterior Color,secondary,prime,union City Body | — | GM dated |
| 00R | Not Equipped with Heated Rear Outboard Seats, see dealer for details Chevrolet Silverado 1500 | 2022–2023 | Provisional |
| 00U | Ccu, M Primary Color, Exterior, Prime | 1989 | GM dated |
| 00U | P CCU, M PRIMARY COLOR, EXTERIOR, PRIME | 1989 | GM sourced |
| 00U | Exterior Color,primary,prime,upper,union City Body | — | GM dated |
| 00V | Not Equipped with Heated or Ventilated Front Seats, see dealer for details Chevrolet Silverado 1500 | 2022–2023 | Provisional |
| 00Y | Not Equipped with Rear Park Assist, see dealer for details Chevrolet Silverado 1500 | 2022–2023 | Provisional |
| 00Z | Not Equipped with Front and Rear Park Assist, see dealer for details Chevrolet Silverado 1500 | 2022–2023 | Provisional |
| 010 | Rat, M Ratio, 5.43 | 1991 | GM dated |
| 010 | P RAT, M RATIO, 5.43 | 1991 | GM sourced |
| 011 | Rat, M Ratio, 5.57 (5 4/7) | 1991 | GM dated |
| 011 | P RAT, M RATIO, 5.57 (5 4/7) | 1991 | GM sourced |
| 012 | Rat, M Ratio, 5.83 | 1991 | GM dated |
| 012 | P RAT, M RATIO, 5.83 | 1991 | GM sourced |
| 013 | Rat, M Ratio, 3.73 | 1995 | GM dated |
| 013 | P RAT, M RATIO, 3.73 | 1995 | GM sourced |
| 014 | Rat, M Ratio, 6.14 (6 1/7) | 1991 | GM dated |
| 014 | P RAT, M RATIO, 6.14 (6 1/7) | 1991 | GM sourced |
| 015 | Rat, M Ratio, 6.17 | 1991 | GM dated |
| 015 | P RAT, M RATIO, 6.17 | 1991 | GM sourced |
| 016 | Rat, M Ratio, 5.25 | 1991 | GM dated |
| 016 | P RAT, M RATIO, 5.25 | 1991 | GM sourced |
| 017 | Rat, M Ratio, 6.50 | 1991 | GM dated |
| 017 | P RAT, M RATIO, 6.50 | 1991 | GM sourced |
| 018 | Rat, M Ratio, 6.65 | 1989 | GM dated |
| 018 | P RAT, M RATIO, 6.65 | 1989 | GM sourced |
| 019 | Rat, M Ratio, 6.67 | 1989 | GM dated |
| 019 | P RAT, M RATIO, 6.67 | 1989 | GM sourced |
| 01A | Stc, R Stripe Color, Accent, Two Tone, Silver/gunmetal (1995) | 1998 | GM dated |
| 01A | P STC, R STRIPE COLOR, ACCENT, TWO TONE, SILVER/GUNMETAL (1995) | 1998 | GM sourced |
| 01A | Stripe Color Accent, Two Tone, Silver/gunmetal | — | GM dated |
| 01A | Trim Color Seat Jet Black | — | GM dated |
| 01B | Trim Color Seat LT Neutral | — | Reference |
| 01C | Trim Color Seat LT Titanium | — | Reference |
| 01D | Trim Color Seat LT Cashmere | — | Reference |
| 01E | Trim Color Seat DK Titanium | — | Reference |
The full list, A to Z
Showing 401–458 of 458 codes beginning with N. One meaning shown per code — the best-sourced one we hold. Search above for the rest.
| Code | Meaning | Years | Sourcing |
|---|---|---|---|
| NWZ | Steering Power, Non-variable Ratio, Light Variable Effort Hydraulic | — | Reference |
| NX0 | P, WHL, M, WHEEL, 16 X 5.5 | 1987 | Provisional |
| NX1 | P, WHL, M, WHEEL, 13 X 5.5, ALUMINUM (LMA) | 1997 | GM sourced |
| NX2 | P, WHS, R, WHEEL SPARE, 15 X 6.0 ALUMINUM | 1998 | Provisional |
| NX3 | P, WHL, M, WHEEL, 16 X 6, 5 HOLE | 1996 | Provisional |
| NX4 | P, WHL, M, WHEEL, 14 X 5.5, STEEL, 14 ROUND HOLES, HEAVY DUTY | 1998 | Provisional |
| NX5 | P, WHL, M, WHEEL, 16 X 6.5, ALUMINUM, SPORT | 1998 | GM sourced |
| NX6 | P, WHL, M, WHEEL, 16 X 6, 6 HOLE | 1996 | Provisional |
| NX7 | Wheel 17 X 7.5, Steel | — | Reference |
| NX8 | P, WHL, M, WHEEL, 14 X 6, ALUMINUM (LMA) this code has more than one documented meaning — filter by year | 1997 | GM sourced |
| NX9 | P, TCS, R, TRACTION CONTROL, ELECTRONIC - DELETE | 1998 | GM sourced |
| NXB | Steering Power, Non-variable Ratio, Reduced Rack Travel | — | Reference |
| NXC | Steering Power, Variable Effort, Reduced Rack Travel | — | Reference |
| NXM | P, FUEL, ADDITIONAL- 10 GALLONS | 1999 | GM sourced |
| NXN | P, FUEL, ADDITIONAL- 15 GALLONS this code has more than one documented meaning — filter by year | 1997 | GM sourced |
| NXR | P, SRS, R, STEERING, POWER, MAGNETIC SPEED, REDUCED EFFORT, VARIABLE ASSIST, 10813 E, 0 | — | Provisional |
| NXW | P, SRS, R, STEERING, POWER, MIDLAND ROSS this code has more than one documented meaning — filter by year | 1996 | GM sourced |
| NXX | P, EVAPORATIVE SYSTEM, FEDERAL this code has more than one documented meaning — filter by year | 1991 | GM sourced |
| NXY | P, SRS, R, STEERING, POWER, ZF this code has more than one documented meaning — filter by year | 1994 | GM sourced |
| NY1 | P, SHIELD, FUEL TANK this code has more than one documented meaning — filter by year | 1983 | GM sourced |
| NY2 | P, SHIELD, ENGINE, LOWER this code has more than one documented meaning — filter by year | 1999 | GM sourced |
| NY3 | P, WHS, R, WHEEL SPARE, 15 X 6.0 STEEL | 1999 | Provisional |
| NY4 | P, WHS, R, WHEEL SPARE, 14 X 5.5 STEEL | 1999 | Provisional |
| NY5 | P, WHL, M, WHEEL, 13 X 5, STEEL, 12 TRAPEZOIDAL HOLES | 1998 | Provisional |
| NY6 | Gear,power Steering,type 605 | — | Reference |
| NY7 | P, SHIELD, TRANSFER CASE this code has more than one documented meaning — filter by year | 1983 | GM sourced |
| NY8 | P, SHIELD, EXHAUST | 1999 | GM sourced |
| NY9 | P, SHIELD, RADIATOR, LOWER | 1999 | GM sourced |
| NYB | P, TNK, M, FUEL TANK, 227L, 60 GAL, LH, RECT, 18 X 13 this code has more than one documented meaning — filter by year | 1998 | GM sourced |
| NYD | Wheel Spare 18 X 4.0, J, Steel, Design 1 | — | Reference |
| NYG | Wheel Spare 19 X 8.0, J, Aluminum, Design 2 | — | Reference |
| NYH | Wheel Spare 19 X 8.0, J, Aluminum, Design 3 | — | Reference |
| NYJ | Wheel Spare 16 X 7.0, J, Steel, Design 2 | — | Reference |
| NYK | Wheel Spare 19 X 8.0, J, Aluminum, Design 4 | — | Reference |
| NYS | P, SRS, R, STEERING, FOUR WHEEL this code has more than one documented meaning — filter by year | 1998 | GM sourced |
| NYT | C, FLP, R, FLEET SALES, N.Y. TELEPHONE | 1993 | GM sourced |
| NZ0 | P, WHL, M, WHEEL, 16 X 6, ALUMINUM, STYLED, 5 SPOKES, 20703 E, 0 | — | GM sourced |
| NZ1 | P, WHS, R, WHEEL SPARE, 13 X 4.5 STEEL, 314 E, 5 | — | GM sourced |
| NZ2 | P, WHS, R, WHEEL SPARE, 13 X 5 STEEL, 828 E, 5 | — | Provisional |
| NZ3 | P, WHS, R, WHEEL SPARE, FULL SIZE, 16" STEEL, 20118 | — | GM sourced |
| NZ4 | Wheel Spare Full Size, 17' Steel | — | Reference |
| NZ6 | Wheel 16 X 6.5, Steel, High Vent | — | Reference |
| NZ7 | Wheel 16 X 7, Chrome Appearance | — | Reference |
| NZA | Control Steering Wheel, Wireless Interface, Radio & Phone Handsfree | — | Reference |
| NZC | Wheel 13 X 4.5, J, Steel, Design 1 | — | Reference |
| NZD | Wheels, 20 inch Polished aluminum wheels with technical gray painted accents | 2026 | GM sourced |
| NZG | Wheel 20 X 9.0, J, Aluminum, Design 7 | — | Reference |
| NZH | Wheels, 20 inch x 9 inch | 2026 | GM sourced |
| NZJ | Wheels, 20 x 9 inch | 2022 | Provisional |
| NZK | Control Steering Wheel, Cruise Control Switch | — | Reference |
| NZL | Control Steering Wheel, Radio/cruise Ctrl, Redundant Ctrls | — | Reference |
| NZM | Wheels, 20 inch x 9 inch Polished aluminum | 2019 | Reference |
| NZN | Wheels, 20 inch x 9 inch Painted aluminum with machined face and Grazen Painted accents | 2026 | GM sourced |
| NZP | Wheels, 20 inch x 9 inch | 2026 | GM sourced |
| NZT | Wheels, 20 inch x 9 inch painted aluminum with machined face and Gray accent | 2019 | Reference |
| NZV | Wheels, 20 inch x 9 inch machined aluminum with Charcoal pockets | 2026 | GM sourced |
| NZW | Wheels, 20 inch x 9 inch High Gloss Black aggressive aluminum | 2026 | GM sourced |
| NZZ | skid-plate package | 2026 | GM sourced |
Using the master list
This is the full GM RPO code list we hold — every Regular Production Option code in the database, searchable by code or by description and filterable to a single model year. Most RPO lists on the internet run to a couple of hundred codes copied from one service manual. This one holds 24,366, and tells you where each meaning came from.
What an RPO code is
RPO stands for Regular Production Option. Every piece of factory equipment on a GM vehicle carries a three-character code, and the ones fitted to your truck are printed on the Service Parts Identification label in the glove box or on the door jamb. G80 is a locking differential, Z71 is an off-road suspension package, K05 is a block heater.
They matter because they are what the factory actually built, not what a listing claims. If you are buying a truck, the label settles the argument. If you are ordering parts, the axle and transmission codes decide which part fits.
Why the same code means different things
GM has reused these codes for decades and across every division. A code that means one thing on a 1978 pickup can mean something unrelated on a 2015 SUV, and plenty of entries in circulation come from bulk listings with no year and no document behind them.
So every entry here is labelled with where it came from. GM sourced means we hold an actual GM document for it. GM dated means it comes from the option master with a date attached. Reference means it is in general circulation with nothing dated behind it — still useful, but treat it as a lead rather than a fact. Filtering by your model year is the single best way to get an answer you can rely on.
Read the codes off your own label
If you have the sticker in front of you, the RPO decoder will read a photo of it and decode every code at once, checked against your model year.
FullSizeChevy.com is not affiliated with, endorsed by, or sponsored by General Motors. Chevrolet, GMC, Cadillac, Silverado, Sierra and related marks are trademarks of General Motors LLC and are used here only to identify applicable vehicles. RPO meanings vary by model year, platform and configuration — verify against your own label before buying parts.