The Toyota Tundra, first manufactured in 1999, featured the second phase of on-board diagnostics (OBD II) that diagnose issues that occur to the truck’s engine and operating system and communicate codes (DTCs, or diagnostic trouble codes) to the computer of the vehicle. OBD II standardized the equipment necessary to scan and read the trouble codes that cause the check-engine light (malfunction indicator light or MIL) to illuminate on the instrument panel. Reading the codes is required to determine what triggered the MIL.
Locate the data link connector (DLC) in the Toyota Tundra under the driver’s side dashboard. It’s on the right hand side of the steering column pointing straight down.
Plug the pocket scanner’s 16-point connector to the data link connector. Because of the DLC’s shape, there is only one way to plug it in correctly.