FG5 - Check For DTC 1390

- Start engine and idle vehicle at operating temperature.

- Key Off.

- Connect Scan Tool.

- Activate Key On Engine Off Self-Test.

- Is DTC 1390 present?

YES -- Go to FG1. FG1 - DTC 1390: Visually Inspect Octane Adjust Connector

NO -- Go to FG6. FG6 - Verify In-Line Connector Shorting Bar Is Installed