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What is OBD-I Codes List?

OBD-I Codes List is a free, no-sign-up lookup for pre-1996 trouble codes. Every page explains what the code means, what usually causes it, and the order of steps to check and fix it. Written for DIYers with no factory service manual. This site covers 68 codes and counting, one make at a time.

OBD-I is not OBD-II

1996-and-newer cars speak OBD-II: five-digit P-codes read by any scanner. Older cars speak OBD-I: short numeric codes read by counting check-engine flashes. Same dashboard light, different language. For 1996-and-newer codes, see OBD Codes List.

Diagnose before you spend

Follow the steps. Confirm the fault before replacing parts.