Self Test Output (STO)
NOTE:
Enter this test only when codes cannot be retrieved or when directed by SELF TEST INPUT (STI).
STO CIRCUIT PIN IDENTIFICATION
| Circuit | Breakout Box Pin | ECA Pin |
|---|---|---|
| STO | 17 | 1F |
1) Checking System Integrity Visually check all wiring and connectors for evidence of damage, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.
2) Install breakout box and leave ECA disconnected. Check for continuity between STO test pin and STO diagnostic connector terminal. If continuity is not present, repair circuit between ECA and STO diagnostic connector. If continuity is present, go to step 3.
3) Check for continuity between the STO test pin and all other test pins. If continuity is present between the STO test pin and any other test pin, circuit is shorted. Repair as necessary. If not, return to H - "Engine Type" TESTS W/O CODES article in this section.