Health check
1. Start the engine and let it warm up to operating temperature. Disconnect the EACV hose from the air filter and, after bringing the engine speed to about 3500 rpm, feel with your hand the presence of a vacuum in the hose. Quickly close the throttle and recheck for vacuum in the hose.
2. If there is vacuum in the hose and the ENGINE CONTROL light is off, the EACV mechanism is working properly. If there is no vacuum in either the first or second case, and the ENGINE CONTROL light is off, then. there is an air leak between the EACV and the intake manifold, or the EACV mechanism is malfunctioning.
3. Stop the engine and pull out the EACV electrical connector. Check the resistance between the contacts, it should be 8-15 ohms. Also check the resistance between each pin and ground - it should be infinite (lack of ground contact). If any of these tests give a negative result, then the EACV should be replaced.
4. Pull out the main connector of the ECU and check the wiring between pins A1 and A3 of the EACV and ECU. With the contacts of the EACV device connected to each other, the resistance between the indicated contacts A1 and A3 must be 815 ohms. Also check for a good ground connection on terminals A24 and A26.
5. If all tests are positive, then pull the ECU fuse located in the relay box under the engine hood for 10 seconds to clear the fault codes. Then test drive the vehicle and check if the EACV still malfunctions. However, if a tested and working ECU is available, then it should be installed during a road test.