EGR Control Solenoid Valve
- Disconnect vacuum hose at EGR valve. See Fig 1
. Connect vacuum gauge to hose. Warm engine until cooling fan comes on. Increase engine speed to about 3000 RPM. Observe vacuum gauge. If vacuum is present, solenoid is okay. If vacuum is not present, go to next step
Courtesy of AMERICAN HONDA MOTOR CO., INC.
- Disconnect connector from EGR control solenoid valve. Turn ignition on. Connect voltmeter negative lead to ground. Backprobe Black/Yellow wire terminal at connector. If voltage is not present, check for blown fuse or open or short in EGR control solenoid Black/Yellow power supply wire.
- If voltage is present, increase engine speed to about 3000 RPM. Check for voltage across solenoid terminals. If voltage exists but vacuum is not present, check for restricted hose. If hose is okay, replace defective solenoid.
- If voltage is not present, check for open in ground wire to solenoid. See appropriate wiring diagram in WIRING DIAGRAMS
article in the ENGINE PERFORMANCE Section. If ground wire is okay, substitute a known good ECU and retest. If problem goes away, replace original ECU.