Toyota pre-OBD2 diagnostic connector is a 17-pin rectangular connector used on Toyota and Lexus vehicles from approximately 1988 to 1995. The T and E1 pins are bridged with a jumper to enter diagnostic mode.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | VF1 | Diagnostic voltage signal 1 | BUS |
| 2 | VF2 | Diagnostic voltage signal 2 | BUS |
| 3 | OX | Oxygen sensor voltage | ADC |
| 4 | THW | Coolant temperature signal | ADC |
| 5 | THA | Intake air temperature | ADC |
| 13 | T | Diagnosis request terminal | I/O |
| 14 | TE1 | Engine diagnostic enable | I/O |
| 15 | E1 | Ground for diagnosis | GND |
| 16 | BAT | Battery 12V | PWR |