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Home >> Mazda >> 1997 >> Millenia Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests - 2.5L >> Idle Control System >> By-Pass Air Control (BAC) Valve
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By-Pass Air Control (BAC) Valve

  1. BAC valve is located underneath throttle body.
  2. Ensure engine is cold. Start engine and let it idle. Idle speed should gradually decrease as engine reaches normal operating temperature. If idle speed does not decrease, check coolant hose to BAC valve. Repair as necessary. If coolant hose is okay, replace BAC valve.