The OBD1 to OBD2 12-pin connection cable for GM cars is the solution for those who want to troubleshoot older General Motors vehicles that use GM's OBD1 protocol, but with modern OBD2 equipment. With this adapter cable, you can easily connect an OBD2 scanner to the car's OBD1 port (12-pin) – and read fault codes, reset engine lights, and monitor vehicle data, directly on your mobile or via computer.
This type of cable is indispensable for car owners, hobby mechanics, or workshops working with GM cars from the early 90s up to the mid-90s.
What does this OBD1 to OBD2 cable do?
This cable converts GM's 12-pin OBD1 port (usually a black, flat connector) to a standard OBD2 female connector – allowing you to:
🔧 Use your OBD2 diagnostic equipment (e.g., ELM327, scanner)
🚗 Troubleshoot engine faults, check sensor data, read DTC codes
✅ Work with GM vehicles from 1982–1995 (varies by model)
🧩 Avoid replacing equipment – keep your OBD2 reader
💡 Note: OBD1 does not provide as much data as OBD2 – some functions may be limited depending on the car model and reader.
Compatible GM cars
Often used with models such as:
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Chevrolet (e.g., Blazer, S10, Suburban, Camaro, Corvette)
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GMC (Jimmy, Safari, Sonoma)
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Pontiac (Grand Prix, Firebird)
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Buick (Regal, Century)
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Oldsmobile (Cutlass, Bravada)
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Other GM cars from 1982–1995
👉 Make sure the car has a 12-pin ALDL port (usually under the steering wheel, sometimes in the center console) and that your scanner/app supports OBD1 data.
Technical specifications
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🔌 Input: 12-pin (male) GM OBD1 connector
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📤 Output: Standard 16-pin OBD2 (female)
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🔋 Passive adapter – requires no external power supply
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⚠️ Physical adapter only – requires compatible software/reader
How it works
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Connect the 12-pin connector to the car's OBD1 port
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Connect your OBD2 reader or ELM327 to the cable
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Use an app or software that supports GM OBD1 data
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Read fault codes or sensor data (if available)
💡 Some cars also require shorting two pins (e.g., A–B) to manually flash fault codes via the engine light – this can be done without a scanner.
Important to know
✅ This cable converts the connector, but not the protocol – your OBD2 scanner must support GM OBD1, otherwise it will not work.
✅ ELM327 with the correct app (e.g., OBD Auto Doctor, Torque Pro) can in some cases read data – but not all apps support OBD1.
✅ For deeper diagnostics, a specific GM Tech 1 or Tech 2 unit is recommended.
Common uses
🛠️ Troubleshoot older GM cars that do not have an OBD2 port
🧠 Reset fault codes or check sensor data
🔍 Pre-inspection / troubleshooting at home in the garage
📦 Extend the functionality of your existing diagnostic equipment
Frequently asked questions
Does this work with all 90s GM cars?
No – it works with many, but not all. Check that your car has a 12-pin GM ALDL port and that your diagnostic equipment supports OBD1.
Do I need a separate power supply?
No – power is drawn directly from the car via the 12-pin port.
Does it work with iPhone apps?
Only if you have a Wi-Fi-based OBD2 reader and the app supports GM OBD1.
Is this a complete troubleshooting solution?
It is an adapter. You still need a scanner or app that can interpret GM OBD1 data.
Why customers choose our OBD1 to OBD2 cables
✅ Quality cables with correct pinout
✅ Clear information on compatibility
✅ Secure e-commerce & fast delivery
✅ Support that understands both old and new car systems
Summary: Solve GM fault codes easily
With an OBD1 to OBD2 12-pin connection cable for GM, you get access to important vehicle data from older GM cars – without having to invest in old specialized equipment. Perfect for troubleshooting, code reading, and simpler repairs, directly with your existing OBD2 scanner.
For those who want to understand their car better – even if it was built before 1996.
