BAC (Bypass Air Control) Valve

BAC VALVE OPERATION INSPECTION

1. Connect the SST (System Selector) to the data link connector.
2. Set switch A to position 1.




3. Set the test switch to SELF TEST.
4. Connect the SSTs (NGS) to the data link connector-2.
5. Select the PID-DATA MONITOR AND RECORD function.
6. Verify that the engine is cold condition, and start the engine.
7. Select the "RPM" on the NGS display.
8. Verify that the engine speed decreases as the engine warms up.
9. Disconnect the SST (System Selector).
10. If the engine speed will not decrease or decreases slowly, check the water hose connected to the BAC valve for leakage and clogs.
11. If the water hose is okay, inspect the following.
- Air valve
- IAC valve