Special Tool - Hand Tester: 57001-1394
Exhaust Butterfly Valve Actuator Resistance
Connections: P lead ←→ GY lead
Standard: 5 
200 Ω (for reference)
If the reading is 0 or infinity (∞) Ω, replace the exhaust butterfly valve actuator.
If the reading is in specification, remove the ECU and check the wiring for continuity between main harness connectors.
Disconnect the ECU and actuator connectors.
Wiring Inspection ECU Connector [A] ←→ Exhaust Butterfly Valve Actuator Connector [B] W/R lead (ECU terminal 45) [C] W/BL lead (ECU terminal 46) [D]
If the wiring is good, check the ECU for its ground and power supply (see ECU Power Supply Inspection in the Fuel System (DFI) chapter).
If the ground and power supply are good, replace the ECU (see ECU Removal/Installation in the Fuel System (DFI) chapter).
Exhaust Butterfly Valve Actuator Circuit
1. ECU
2. Exhaust Butterfly Valve Actuator
Exhaust Butterfly Valve Actuator Inspection
Air Switching Valve (Service Code 64)Fuels Containing Oxygenates
Gasoline frequently contains oxygenates
(alcohols and ethers) especially
in areas of the U.S. and Canada
which are required to sell such reformulated
fuels as part of a strategy to
reduce exhaust emissions.
The types and volume of fuel oxygenates
approved for use in unleaded
gasoline by th ...
Fuse Inspection
Remove the fuse.
Inspect the fuse element.
If it is blown out, replace the fuse. Before replacing a
blown fuse, always check the amperage in the affected
circuit. If the amperage is equal to or greater than the
fuse rating, check the wiring and related components for
a short circuit.
...
DFI System Wiring Diagram (KIBS Equipped Models)
1. Air Intake Solenoid Valve (Other than US, CA and CAL Models)
2. Engine Stop Switch
3. Starter Button
4. Air Switching Valve
5. Stick Coil #1, #2, #3, #4
6. Spark Plugs
7. Intake Air Temperature Sensor
8. Crankshaft Sensor
9. Secondary Fuel Injector #1
10. Secondary Fuel Injector #2
...