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Home >> Mazda >> 1997 >> MX-5 Miata L4-1.8L DOHC >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Relays and Modules - Computers and Control Systems >> Idle/Throttle Speed Control Unit >> Testing and Inspection >> Operational Test
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Operational Test




BAC Valve Operational Inspection




1. Connect the Special Service Tools New Generation Star (NGS) tester to the data link connector-2.




2. Select "PID/DATA MONITOR AND RECORD" and press TRIGGER.
3. Select "RPM" and press TRIGGER.
4. Verify that the engine is in cold condition, then start the engine.
5. Verify that the engine speed decreases as the engine warms up.
6. If the engine speed does not decrease or decreases slowly, check the water hose connected to the BAC valve for leakage and clogs.
7. If the water hose is okay, inspect the following.
- Air valve.
- Idle air control valve.
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