17-14
ENGINE AND EMISSION CONTROL ±
Throttle
body
EGR valve
Emission Control System
EXHAUST GAS RECIRCULATION (EGR)
CONTROL SYSTEM CHECK
Refer to GROUP 13A ± Troubleshooting.
EGR VALVE (STEPPER MOTOR) CHECK
Checking the Operation Sound
1. Check that the operation sound of the stepper motor can
be heard from the EGR valve when the ignition switch
is turned to ON (without starting the engine).
2. If the operation sound cannot be heard, check the stepper
motor drive circuit.
NOTE
If the circuit is normal, the cause is probably a malfunction
of the stepper motor or of the engine-ECU.
Checking the Coil Resistance
1. Disconnect the EGR valve connector.
2. Measure the resistance between the EGR valve-side
connector terminal No.2 and terminal No.1 or terminal
No.3.
Standard value: 10 ± 20 Ω (at 20 C)
3. Measure the resistance between the EGR valve-side
connector terminal No.5 and terminal No.4 or terminal
No.6.
Standard value: 10 ± 20 Ω (at 20 C)