Idle-Up System Test - 4WD (4A-FE)
- Ensure all accessories are switched off. Air control valve is powered by Black/Red wire from the EFI main relay. ECU controls valve ground.
- Air control valve should be activated during cranking and for 10 seconds after engine starts. Check for battery voltage at air control valve during cranking and after engine starts. If voltage not present, check wiring from EFI main relay, and wiring to "V-ISC" terminal at ECU.
- To check air control valve, see Fig 1.
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