← 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 1–100 of 633 codes beginning with M. One meaning shown per code — the best-sourced one we hold. Search above for the rest.
| Code | Meaning | Years | Sourcing |
|---|---|---|---|
| M01 | P, CLU, R, CLUTCH, 11 IN, SPECIAL | 1998 | Provisional |
| M02 | P, CLU, R, CLUTCH, 14.5 IN, SINGLE PLATE , PULL TYPE, ORGANIC | 1998 | Provisional |
| M08 | P, TRN, M, TRANSMISSION, AUTO 4 SPD, AISIN, AW30-40LE, 2.804 1ST, 0.705 4TH, 20516 E, 8 | — | GM sourced |
| M09 | P, TRN, M, TRANSMISSION, AUTO 5 SPD, AISIN, AF33, (TIPTRONIC), 20530 | — | GM sourced |
| M10 | Transmission Man 6 Spd, Tremec, 85mm, 3.01 1st, 0.84 5th,0.57 6th, O/d this code has more than one documented meaning — filter by year | — | Reference |
| M11 | P, TRN, M, TRANSMISSION, MAN 5 SPD, SUZUKI, 3.42 1ST, 0.76 5TH | 1998 | GM sourced |
| M12 | P, TRN, M, TRANSMISSION, MAN 6 SPD, TREMEC, 85MM, 2.97 1ST, 0.57 6TH, O/D this code has more than one documented meaning — filter by year | 1999 | GM sourced |
| M13 | P, TRN, M, TRANSMISSION, AUTO 4 SPD, HMD, 4T60-E, ELECTRONIC | 1997 | GM sourced |
| M14 | P, TRN, M, TRANSMISSION, MAN 7 SPD, ISUZU, MLD 7Q, 135MM, 7.17 1ST, O/D | 1997 | Provisional |
| M15 | P, TRN, M, TRANSMISSION, AUTO 4 SPD, HMD, 4T65-E, ENHANCED ELECTRONIC this code has more than one documented meaning — filter by year | 1997 | GM sourced |
| M16 | P, TRN, M, TRANSMISSION, CONTINUOUSLY VARIABLE RATIO, GM, X15F-PTU,, VT25-E AWD, ELECTRONIC, 413 | — | GM sourced |
| M17 | P, TRN, M, TRANSMISSION, AUTO 5 SPD, HMD, 5L60-E, ELECTRONIC, O/D this code has more than one documented meaning — filter by year | 1998 | GM sourced |
| M18 | P, TRN, M, TRANSMISSION, AUTO 5 SPD, HMD, 5L80-E, ELECTRONIC, O/D this code has more than one documented meaning — filter by year | 1998 | GM sourced |
| M19 | P, TRN, M, TRANSMISSION, CONTINUOUSLY VARIABLE RATIO, GM, X19F, ELECTRONIC this code has more than one documented meaning — filter by year | 1998 | GM sourced |
| M1A | P, CONTROL, TRANS SHIFT, COLUMN | 1998 | Provisional |
| M1B | P, LOCAL, 0016526 | 1992 | GM sourced |
| M1F | P, POWER TAKE OFF, RR PTO this code has more than one documented meaning — filter by year | 1998 | GM sourced |
| M1J | P, LAMP, FOG, RR ADDITIONAL | 1998 | GM sourced |
| M20 | P, TRN, M, TRANSMISSION, MAN 4 SPD, 117MM, 6.55 1ST | 1983 | GM sourced |
| M21 | P, TRN, M, TRANSMISSION, MAN 4 SPD, 82MM, 2.43 1ST this code has more than one documented meaning — filter by year | 1983 | GM sourced |
| M22 | P, TRN, M, TRANSMISSION, AUTO 5 SPD, HMD, 5L50-E, ELECTRONIC, O/D this code has more than one documented meaning — filter by year | 1999 | GM sourced |
| M23 | P, TRN, M, TRANSMISSION, MAN 6 SPD, GETRAG, 85MM, 3.57 1ST | 1997 | Provisional |
| M24 | P, TRN, M, TRANSMISSION, MAN 5 SPD, OPEL, 2.136 2ND, 1.414 3RD, 1.121 4TH, 0.892 5TH, F13 (CR) | 1997 | Provisional |
| M25 | P, TRN, M, TRANSMISSION, MAN 5 SPD, OPEL, 65MM, 3.727 1ST, 2.136 2ND,, 1.414 3RD, 1.121 4TH, 0.892 5TH, F17 (CR) | 1999 | GM sourced |
| M26 | P, TRN, M, TRANSMISSION, MAN 5 SPD, OPEL, 65 MM, 1.96 2ND, 1.323 3RD,, 0.946 4TH, 0.756 5TH, F17 (WR) | 1999 | GM sourced |
| M27 | P, TRN, M, TRANSMISSION, MAN 5 SPD, BRAZIL, 65 MM, 3.727 1ST, 1.323 3RD, 0.756 5TH (F15 WR) | 1999 | GM sourced |
| M28 | P, TRN, M, TRANSMISSION, MAN 5 SPD, BRAZIL, 65 MM, 3.727 1ST, 1.414 3RD, 0.892 5TH (F17 CR), HD, 10821 E, 5 | — | GM sourced |
| M29 | P, TRN, M, TRANSMISSION, MAN 5 SPD, OPEL, 1.96 2ND, 1.323 3RD, 0.854 4TH, 0.674 5TH, F17 (WR) | 1999 | GM sourced |
| M2A | Transmission Auto 6 Spd, 6t30 | — | Reference |
| M2D | Transmission Auto 6 Spd, 6t50, Gen 2, Var 1 | — | Reference |
| M30 | 4L60-E four-speed electronic automatic transmission | 2007 | GM sourced |
| M31 | P, TRN, M, TRANSMISSION, AUTO 5 SPD, HMD, X5R this code has more than one documented meaning — filter by year | 1997 | GM sourced |
| M32 | heavy-duty 4L60-E four-speed automatic transmission | 2007 | GM sourced |
| M33 | hybrid-calibrated 4L60-E four-speed automatic transmission | 2007 | GM sourced |
| M34 | P, TRN, M, TRANSMISSION, MAN 5 SPD, GETRAG, 84MM, 3.553 1ST | 1998 | Provisional |
| M35 | P, TRN, M, TRANSMISSION, MAN 5 SPD, GETRAG, 76MM, 3.83 1ST, 0.81 5TH | 1998 | GM sourced |
| M36 | P, TRN, M, TRANSMISSION, AUTO 6 SPD, AISIN-WARNER, A6-F40, ELECTRONIC, 10531 E, 0 | — | GM sourced |
| M37 | P, TRN, M, TRANSMISSION, MAN 5 SPD, ZFS5-42, 105MM, 5.08 1ST, O/D | 1992 | Provisional |
| M38 | P, TRN, M, TRANSMISSION, MAN 5 SPD, OPEL, 77 MM, 3.58 1ST, 0.66 5TH (F35WR), 10411 E, 0 | — | GM sourced |
| M39 | Transmission,manual 5-speed(borg-warner) | — | Reference |
| M3L | Transmission Man 6 Spd this code has more than one documented meaning — filter by year | — | Reference |
| M3N | Transmission Man 6 Spd, Opel, 76.5 Mm, 4.273 1st, 0.861 6th | — | Reference |
| M40 | P, TRN, M, TRANSMISSION, AUTO 3 SPD, TORQUE CONV, VAR 1 this code has more than one documented meaning — filter by year | 1984 | GM sourced |
| M41 | P, TRN, M, TRANSMISSION, AUTO 4 SPD, 2.826 1ST, 0.730 4TH this code has more than one documented meaning — filter by year | 1995 | GM sourced |
| M42 | P, TRN, M, TRANSMISSION, MAN 5 SPD, SUZUKI, 3.583 1ST, 0.757 5TH this code has more than one documented meaning — filter by year | 1995 | GM sourced |
| M43 | P, TRN, M, TRANSMISSION, AUTO 5 SPD, OPEL, AF23 | 1998 | GM sourced |
| M44 | P, TRN, M, TRANSMISSION, AUTO/MAN 5 SPEED, OPEL, F17, 0.89 5TH, ELECTRONIC,(CR), (TIPTRONIC), 10507 E, 0 | — | Provisional |
| M45 | P, TRN, M, TRANSMISSION, AUTO 5 SPD, OPEL, AF33, (TIPTRONIC), 20530 E, 0 | — | GM sourced |
| M46 | P, TRN, M, TRANSMISSION, MAN 5 SPD, CLARK, CL2205, 70MM, 3.92 1ST | 1998 | Provisional |
| M47 | P, TRN, M, TRANSMISSION, MAN 5 SPD, CLARK, CL2615, 109MM, 5.82 1ST | 1998 | Provisional |
| M48 | P, TRN, M, TRANSMISSION, MAN 5 SPD, CLARK, CL2615, 109MM, 6.80 1ST | 1998 | Provisional |
| M49 | P, TRN, M, TRANSMISSION, MAN 5 SPD, TREMEC, 77MM, 3.75 1ST, 0.76 5TH, O/D | 1999 | GM sourced |
| M4A | P, SALES PACKAGE, EXECUTIVE - VAR 1 | 1999 | GM sourced |
| M4B | P, SALES PACKAGE, EXECUTIVE - VAR 2 | 1999 | GM sourced |
| M4E | Transmission Man 5 Spd, 3.73 1st, 2.14 2nd, 1.41 3rd, 1.12 4th 0.89 5th, F15cr, Gen2 | — | Reference |
| M4L | Transmission Man 5 Spd, 4.27 1st, 2.35 2nd, 1.48 3rd, 1.05 4th 0.805th, F17-hr, Gen2 | — | Reference |
| M4M | Transmission Auto, Continuously Variable Ratio (cvt), Fwd, Jatco, Va7 | — | Reference |
| M4P | Transmission Man 5 Spd, Gmap, 72mm, Fwd, 3.81 1st, 2.15 2nd, 1 .34 3rd, 0.97 4th, 0.76 5th, D16 | — | Reference |
| M50 | P, TRN, M, TRANSMISSION, MAN 5 SPD, NVG, 85MM, 3.49 1ST, O/D this code has more than one documented meaning — filter by year | 1997 | GM sourced |
| M51 | P, TRN, M, TRANSMISSION, MAN 5 SPD, NVG, 85MM, 3.49 1ST, 0.73 5TH, O/D, 417 | — | GM sourced |
| M52 | P, TRN, M, TRANSMISSION, MAN 5 SPD, GETRAG, F23, TFWD, 10912 | — | Provisional |
| M53 | Shifter Interlock Clutch | — | Reference |
| M54 | P, TRN, M, TRANSMISSION, MAN 6 SPD, ISUZU, 136MM, 6.72 1ST, O/D this code has more than one documented meaning — filter by year | 1999 | GM sourced |
| M55 | P, TRN, M, TRANSMISSION, MAN 5 SPD, CLARK, CL2905, 4.47 1ST, .81 5TH, O/D | 1998 | GM sourced |
| M56 | P, TRN, M, TRANSMISSION, MAN 5 SPD, CLARK, CL2905, 4.08 1ST, .815 5TH, O/D | 1998 | Provisional |
| M57 | P, TRN, M, TRANSMISSION, MAN 5 SPD, CLARK, CL3905, 5.08 1ST, .77 5TH, O/D | 1998 | Provisional |
| M58 | P, TRN, M, TRANSMISSION, MAN 5 SPD, SUZUKI, 3.416 1ST, 0.757 5TH this code has more than one documented meaning — filter by year | 1995 | GM sourced |
| M59 | P, TRN, M, TRANSMISSION, MAN 5 SPD, SUZUKI, 3.65 1ST, 0.795 5TH this code has more than one documented meaning — filter by year | 1995 | GM sourced |
| M5N | Transmission Auto 8 Spd, 8l45, Bas+ | — | Reference |
| M5T | Transmission Auto 8 Spd, 8l45 | — | Reference |
| M5U | Transmission Auto 8 Spd, 8l90 | — | Reference |
| M60 | P, TRN, M, TRANSMISSION, AUTO 3 SPD, SUZUKI, 2.810 1ST, 1.00 3RD this code has more than one documented meaning — filter by year | 1994 | GM sourced |
| M61 | P, TRN, M, TRANSMISSION, AUTO 4 SPD, SAAB, TFWD this code has more than one documented meaning — filter by year | 1994 | GM sourced |
| M62 | P, TRN, M, TRANSMISSION, MAN 5 SPD, BRAZIL, 65 MM, 3.727 1ST, 1.323 3RD, 0.756 5TH AUTOMATIC CLUTCH SYSTEM (F17 WR), 414 E, 5 | — | GM sourced |
| M63 | P, TRN, M, TRANSMISSION, MAN 5 SPD, OPEL, 77MM, 3.58 1ST, 0.71 5TH (F35 WR), 10410 E, 0 | — | GM sourced |
| M64 | Transmission,manual 3-speed(muncie) | — | Reference |
| M65 | Transmission Auto 3 Spd, Suzuki, 2.40 1st, 1.00 3rd this code has more than one documented meaning — filter by year | — | Reference |
| M66 | P, TRN, M, TRANSMISSION, MAN 9 SPD, EATON-FULLER, 9L160M | 1997 | GM sourced |
| M67 | Transmission,manual 4-speed(muncie) | — | Reference |
| M68 | P, TRN, M, TRANSMISSION, AUTO 4 SPD, JATCO, ISUZU, A4-JATCO, ELECTRONIC | 1995 | GM sourced |
| M69 | P, TRN, M, TRANSMISSION, MAN 6 SPD, EATON, FS08406, 6.62 1ST, O/D this code has more than one documented meaning — filter by year | 1998 | GM sourced |
| M6A | P, WRM, R, WARRANTY MANUAL, FRENCH - RENAULT, 20430 | — | Provisional |
| M6B | P, WRM, R, WARRANTY MANUAL, SPANISH - RENAULT, 20430 | — | Provisional |
| M6C | P, MANUAL, MAINTENANCE - EUROPE - INTERNATIONAL VAR 1, 10613 | — | Provisional |
| M6D | P, MANUAL, MAINTENANCE - EUROPE - INTERNATIONAL VAR 2, 10613 | — | Provisional |
| M6E | P, MANUAL, MAINTENANCE - EUROPE - INTERNATIONAL VAR 3, 10613 | — | Provisional |
| M6F | P, MANUAL, MAINTENANCE - EUROPE - INTERNATIONAL VAR 4, 10613 | — | Provisional |
| M6G | P, MANUAL, MAINTENANCE - EUROPE - INTERNATIONAL VAR 5, 10613 | — | Provisional |
| M6H | P, MANUAL, MAINTENANCE - EUROPE - SOUTH AMERICA VAR 1, 10613 | — | Provisional |
| M6I | P, MANUAL, MAINTENANCE - EUROPE - SOUTH AMERICA VAR 2, 10613 | — | Provisional |
| M6J | P, WRM, R, WARRANTY MANUAL, ENGLISH - RENAULT, 20430 | — | Provisional |
| M6K | P, WRM, R, WARRANTY MANUAL, GERMAN - RENAULT, 20430 | — | Provisional |
| M6L | P, WRM, R, WARRANTY MANUAL, ITALIAN - RENAULT, 20430 | — | Provisional |
| M6M | P, WRM, R, WARRANTY MANUAL, DUTCH - RENAULT, 20430 | — | Provisional |
| M6N | P, WRM, R, WARRANTY MANUAL, PORTUGUESE - RENAULT, 20430 | — | Provisional |
| M6O | P, WRM, R, WARRANTY MANUAL, POLISH - RENAULT, 20430 | — | Provisional |
| M6P | P, WRM, R, WARRANTY MANUAL, CZECH - RENAULT, 20430 | — | Provisional |
| M6Q | P, WRM, R, WARRANTY MANUAL, BELGIAN - RENAULT, 20430 | — | Provisional |
| M6R | P, WRM, R, WARRANTY MANUAL, SWISS - RENAULT, 20430 | — | Provisional |
| M6S | P, WRM, R, WARRANTY MANUAL, AUSTRIAN - RENAULT, 21014 | — | Provisional |
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.