Civic 1500
- Disconnect hose number 23 from surge tank B. Connect a vacuum pump and apply vacuum. Apply 12 volts to frequency solenoid valve B.
- If there is vacuum, go to step 4). If there is no vacuum, pinch the hose closed between frequency solenoid valve B and the constant vacuum valve.
- If vacuum is present, replace the constant vacuum valve and retest. If there is no vacuum, replace the frequency solenoid valve B and retest.
- Disconnect 12 volts from frequency solenoid valve B. If vacuum drops off, frequency solenoid valve B is okay. If not, replace frequency solenoid valve B and retest.