← 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 301–400 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 |
|---|---|---|---|
| MF9 | P, TRN, M TRANSMISSION, AUTO/MAN 5 SPEED, GMB, F17, 0.76 5TH, ELECTRONIC | 1999 | Provisional |
| MFA | Transmission, Auto 4 Spd, 4hp16, Dwpt | — | Reference |
| MFB | Transmission, Manual 5 Spd, D24 S/r | — | Reference |
| MFC | Transmission, 8-speed automatic | 2026 | GM sourced |
| MFD | Transmission, Continuous Variable Ratio, Aichi, Pt08,electronic | — | Reference |
| MFE | Transmission, Man 5 Spd, D20 CR | — | Reference |
| MFF | Transmission, Man 5 Spd, D20 M/r | — | Reference |
| MFG | Transmission, Man 5 Spd, Y4m | — | Reference |
| MFH | Transmission, Man 5 Spd, D16 M/cr | — | Reference |
| MFJ | Transmission, Auto 3 Spd, Jatco, Frb | — | Reference |
| MFL | Transmission, Auto 4 Spd Jatco Jf405e | — | Reference |
| MFM | Transmission Man 5 Spd, Y4m Hd, 1st 3.539, 5th 0.781 | — | Reference |
| MFN | Transmission,man 5 Spd,dwpt-d33,3.820 1st,0.767 5th | — | Reference |
| MFR | Transmission Man 5 Spd, Dwpt-d33, 3.947 1st, 0.767 5th | — | Reference |
| MFU | Transmission Man 5 Spd, D33, 3.820 1st, 0.721 5th | — | Reference |
| MFV | Transmission Man 5 Spd, D33 Super-wide, 3.947 1st, 0.721 5th | — | Reference |
| MG0 | P, TRN, M TRANSMISSION, MAN 5 SPD, OPEL, R25, 4.04 1ST, O/D | 1997 | GM sourced |
| MG1 | P, TRN, M TRANSMISSION, MAN 5 SPD, GETRAG, F23, 75MM, 3.58 1ST, 0.69 5TH, 10912 E, 0 | — | GM sourced |
| MG2 | P, TRN, M TRANSMISSION, MAN 5 SPD, SUZUKI, MFM13, 60MM, 3.454 1ST, 1.904 2ND, 1.280 3RD, 0.966 4TH, 0.815 5TH, 3.272 REV., 11205 E, 8 this code has more than one documented meaning — filter by year | — | GM sourced |
| MG3 | P, TRN, M TRANSMISSION, MAN 5 SPD, GETRAG, F23, 75MM, 3.58 1ST, 2.02 2ND, 1.35 3RD, 0.98 4TH, 0.81 5TH, 10912 E, 0 | — | GM sourced |
| MG4 | P, TRN, M TRANSMISSION, MAN 5 SPD, ISUZU, 72MM, 3.41 1ST, 2.15 2ND, .89 5TH | 1998 | GM sourced |
| MG5 | Getrag five-speed manual transmission | 2007 | GM sourced |
| MG6 | P, TRN, M TRANSMISSION, MAN 5 SPD, GETRAG, F23-PTU, 75MM, 3.58 1ST, 0.69 5TH | 1998 | GM sourced |
| MG7 | P, TRN, M TRANSMISSION, MAN 5 SPD, GETRAG, 75MM, 3.58 1ST, 2.02 2ND, 1.35 3RD, 0.98 4TH, 0.79 5TH | 1999 | GM sourced |
| MG8 | P, TRN, M TRANSMISSION, MAN 5 SPD, EATON, FSO-2405A, 4.08 1ST, 0.725 5TH, O/D, 20603 | — | Provisional |
| MG9 | Transmission Man 6 Spd, Tremec, 85mm, 2.66 1st, 0.63 6th. | — | Reference |
| MGG | Transmission Auto 8 Spd, Aisin, Tl- 80sn, Gmna, Rwd/awd | — | Reference |
| MGM | Transmission, 10-Speed automatic | 2026 | GM sourced |
| MGU | Transmission, 10-Speed automatic with integrated Power Take-Off (PTO) | 2026 | GM sourced |
| MH1 | P, TRN, M TRANSMISSION, AUTO 4 SPD, HMD, 4T80-E, ELECTRONIC CONV CLUTCH | 1998 | GM sourced |
| MH2 | Transmission Auto 6 Spd, Hmd, 6t70 | — | Reference |
| MH3 | P, TRN, M TRANSMISSION, MAN 5 SPD, BORG WARNER, 77MM, 3.50 1ST, .73 5TH, O/D this code has more than one documented meaning — filter by year | 1984 | GM sourced |
| MH4 | Transmission Auto 6 Spd, Hmd, 6t70, Awd/ptu | — | Reference |
| MH5 | P, TRN, M TRANSMISSION, MAN 5 SPD, EATON, FSO-2405B, 4.08 1ST, .81 5TH, O/D, 20708 E, 5 | — | GM sourced |
| MH6 | P, TRN, M TRANSMISSION, AUTO 6 SPD, HMD, X22, PTU, 11017 | — | GM sourced |
| MH7 | Transmission Auto 6 Spd, Hmd, X23fhd | — | Reference |
| MH8 | Transmission Auto 6 Spd, Hmd, X23f | — | Reference |
| MH9 | Transmission Auto 6 Spd, Hmd, X24f | — | Reference |
| MHA | P, TRN, M TRANSMISSION, MAN 6 SPD, EATON, FSO6406A, 125MM, 6.08 1ST, 0.79 6TH, 520 LBS, O/D, 20730 E, 8 | — | Provisional |
| MHB | Transmission Auto 6 Spd, Gmdat, Awd (x23f) | — | Reference |
| MHC | Transmission Auto 6 Spd, Gmdat, Awd, Hd, (x23fhd) | — | Reference |
| MHD | Transmission Auto 6 Spd, Allison, 2350evs, Conv Clutch, With Park Pawl, And Pto | — | Reference |
| MHE | Transmission Auto 6 Spd, Allison, 2350, Conv Clutch, With Park Pawl | — | Reference |
| MHF | Transmission Auto 6 Spd, Allison, 2350mh, Conv Clutch, With Park Pawl | — | Reference |
| MHG | Transmission Auto 6 Spd, Hmd, Gm, Bas+, 6t45, Hybrid, Fwd | — | Reference |
| MHH | Transmission Auto 6 Spd, Hmd, Gm, Bas+, 6t40, Hybrid, Fwd | — | Reference |
| MHJ | Transmission Auto 6 Spd, 6t50, Awd | — | Reference |
| MHK | Transmission Auto 6 Spd, 6t50 | — | Reference |
| MHM | Transmission Auto 6 Spd, Hmd, 6t80, Awd, Gen 2 | — | Reference |
| MHO | Transmission, 10-speed automatic | 2026 | GM sourced |
| MHS | Transmission, 10-speed automatic | 2026 | GM sourced |
| MHT | Transmission, 10-speed automatic, electronically controlled with overdrive and tow/haul mode | 2026 | GM sourced |
| MHU | 10L80 ten-speed automatic transmission | 2026 | GM sourced |
| MI2 | 10-speed automatic transmission with column shift | 2026 | GM sourced |
| MIR | Family Code, Mirror O/s | 1989 | GM dated |
| MJ1 | P, TRN, M TRANSMISSION, MAN 5 SPD, ISUZU, 76MM, 3.5451ST, .829 5TH, O/D | 1992 | GM sourced |
| MJ2 | P, TRN, M TRANSMISSION, MAN 6 SPD, ISUZU, MLD 6, 8.18 1ST, DIRECT DRIVE | 1998 | GM sourced |
| MJ3 | P, TRN, M TRANSMISSION, MAN 5 SPD, DIRECT 6.378 1ST | 1983 | GM sourced |
| MJ6 | P, TRN, M TRANSMISSION, MAN 9 SPD, EATON, FS8209, DIRECT DRIVE, 121 E, 8 | — | Provisional |
| MJ7 | P, TRN, M TRANSMISSION, AUTO 5 SPD, HONDA, 5AT, 128 | — | GM sourced |
| MJ8 | P, TRN, M TRANSMISSION, AUTO 5 SPD, HONDA, 5AT, PTU, 1101 | — | GM sourced |
| MK0 | P, TRN, M TRANSMISSION, MAN 5 SPD, EATON, 7.22 1ST, 1.39 4TH, O/D this code has more than one documented meaning — filter by year | 1998 | GM sourced |
| MK2 | P, TRN, M TRANSMISSION, AUTO 4 SPD, HMD, 4L60-E, ELECTRONIC, PTU, 11017 | — | GM sourced |
| MK3 | Transmission Auto, Electronic Ratio Select, Gm, Strong Hybrid Evt, X25f, Fwd. | — | Reference |
| MK4 | Transmission,manual 5-speed(borg-warner) | — | Reference |
| MK5 | P, TRN, M TRANSMISSION, MAN 5 SPD, TOYOTA, 75MM, 3.17 1ST, 0.72 5TH, 10104 | — | GM sourced |
| MK6 | Transmission Man 6 Spd, Opel, 83mm, 3.92 1st, 0.745 6T this code has more than one documented meaning — filter by year | — | Reference |
| MK7 | P, TRN, M TRANSMISSION, MAN 5 SPD, ISUZU, 3.91 1ST, 1.45 3RD, O/D | 1984 | GM sourced |
| MK8 | P, TRN, M TRANSMISSION, MAN 7 SPD, SPICER, ES56-7B, 10.09 1ST, DIRECT DRIVE, 225 | — | GM sourced |
| MK9 | P, TRN, M TRANSMISSION, MAN 7 SPD, SPICER, ES066-7B, 7.48 1ST, O/D this code has more than one documented meaning — filter by year | 1994 | GM sourced |
| MKA | Transmission Automatic, Electronic Ratio Select, Gm, Strong Hyb Rid, Evt, Plug IN | — | Reference |
| MKD | Transmission Auto, Electronic Ratio Select, Voltec, V-series Gen 1 | — | Reference |
| MKM | Transmission, 10-Speed automatic | 2026 | GM sourced |
| MKR | Transmission Man Fwd 5 Spd, Brazil, 180mm, 3.727 1st | — | Reference |
| ML0 | P, TRN, M TRANSMISSION, MAN 5 SPD, EATON, 7.22 1ST, 1.27 4TH, DIRECT DRIVE this code has more than one documented meaning — filter by year | 1998 | GM sourced |
| ML1 | P, TRN, M TRANSMISSION, MAN 5 SPD, SUZUKI, 3.42 1ST, 0.82 5TH | 1998 | GM sourced |
| ML2 | P, TRN, M TRANSMISSION, MAN 5 SPD, BORG WARNER, 77MM, 4.03 1ST, .72 5TH, O/D this code has more than one documented meaning — filter by year | 1984 | GM sourced |
| ML3 | Transmission Auto 6 Spd, Aisin-warner, A6-af55, Electronic this code has more than one documented meaning — filter by year | — | Reference |
| ML4 | P, TRN, M TRANSMISSION, AUTO 4 SPD, HMD, 4L30-E, CONV CLUTCH | 1997 | GM sourced |
| ML5 | P, TRN, M TRANSMISSION, MAN 5 SPD, OPEL, R65.025, 3.727 1ST, 1.96 2ND, 1.323 3RD, 0.946 4TH, 0.761 5TH, F13 (WR) | 1998 | GM sourced |
| ML6 | P, TRN, M TRANSMISSION, MAN 6 SPD, ZF, 105MM, 5.79 1ST, 0.72 6TH, O/D this code has more than one documented meaning — filter by year | 1998 | GM sourced |
| ML7 | P, TRN, M TRANSMISSION, AUTO 5 SPD, AISIN WARNER, A5-F33-PTU, W/NVG RR WHLDRV | 1999 | GM sourced |
| ML8 | Transmission Man 6 Spd, Opel, 76.5 Mm, 3.818 1st, 1.302 3rd | — | Reference |
| ML9 | Transmission Auto, Electronic Ratio Select,gm, Gen 2, 4-mode Hybrid this code has more than one documented meaning — filter by year | — | Reference |
| MLB | Transmission,manual 5-speed(borg-warner) | — | Reference |
| MLD | FAMILY CODE, MOLDING B/S (OPEL), 413 | — | Provisional |
| MLK | Transmission, Man 5 Spd, D16 M/r | — | Reference |
| MLL | Transmission, Man 5 Spd, D16 Y4a | — | Reference |
| MLM | Transmission, Man 5 Spd, D16 Sw/r | — | Reference |
| MLQ | Transmission, Auto 4 Spd, Aisin, AW 80/81-40 | — | Reference |
| MLS | Transmission, Auto 4 Spd, Aisin, AW 50-40-e | — | Reference |
| MM0 | P, TRN, M TRANSMISSION, MAN 6 SPD, EATON, 9.01 1ST, 520 LBS. CAP., DIRECT DRIVE this code has more than one documented meaning — filter by year | 1998 | GM sourced |
| MM1 | P, MTC, M MERCHANDISED TRANS, AUTO EQUIPMENT | 1999 | GM sourced |
| MM2 | P, TRN, M TRANSMISSION, MAN 7 SPD, ISUZU MLD 7R, 8.18 1ST, O/D | 1986 | Provisional |
| MM3 | P, MTC, M MERCHANDISED TRANS, MANUAL EQUIPMENT | 1999 | Provisional |
| MM4 | four-speed manual transmission | 1990 | GM sourced |
| MM5 | five-speed manual overdrive transmission | 1990 | GM sourced |
| MM6 | P, TRN, M TRANSMISSION, MAN 6 SPD, TREMEC, 85MM, 2.66 1ST, 0.50 6TH, O/D this code has more than one documented meaning — filter by year | 1999 | GM sourced |
| MM7 | P, TRN, M TRANSMISSION, MAN 6 SPD, EATON BOOS SYNC, 9.01 1ST, 560 FT LBS, DIRECT DRIVE this code has more than one documented meaning — filter by year | 1999 | GM sourced |
| MM8 | P, TRN, M TRANSMISSION, MAN 6 SPD, EATON BOOS SYNC, 9.01 1ST, 660 FT LBS, DIRECT DRIVE this code has more than one documented meaning — filter by year | 1999 | 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.