Auxiliary Air Valve (Idle Speed): Testing and Inspection

NOTE: The air valve and the idle air control valve are sub-components of the by-pass air control (BAC) valve assembly. Since the air valve and the idle air control valve operate together during cold engine operation, their function test has been combined as a BAC valve test. Additionally, if the function test results are negative, both components are replaced as an assembly. They are not serviceable separately.






BAC VALVE
System Operation-Air valve
- Perform this inspection when the engine is cold. Engine coolant temperature below 20°C (68°F).

View: Tachometer Connection In Data Link Connector:

1. Connect a tachometer to the data link connector terminal IG-.






2. Connect the special service tool (SST) and set the TEST SWITCH to "SELF TEST" or connect data link connector terminals TEN and GND with a jumper wire.
3. Verify that the engine speed gradually decreases as the engine warms up.
4. Remove the SST or the jumper wire.
5. If not as specified, replace the BAC valve.