Frequency Solenoid B
- Disconnect frequency solenoid B connector. Disconnect lower hose from frequency solenoid valve B and connect vacuum pump. Disconnect upper hose from frequency solenoid valve B and connect vacuum gauge. See Fig 1
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- Apply vacuum to solenoid valve B. If solenoid does not hold vacuum, replace solenoid. If vacuum holds, jumper battery voltage to Green/Black wire terminal of solenoid. Jumper Black wire terminal of solenoid to ground. Apply vacuum.
- If vacuum is indicated on gauge connected to upper hose fitting, go to step 4). If vacuum is not indicated on gauge, replace frequency solenoid valve B.
- Disconnect jumper wires from solenoid terminals. If vacuum is now indicated on gauge, replace frequency solenoid valve B. If vacuum is not indicated on gauge, reconnect vacuum hoses. Start engine and warm to operating temperature (cooling fan comes on).
- Measure voltage between Green/Black (pos.) and Black (neg.) terminals of solenoid harness at about 2500 RPM. If voltage fluctuates 0-12 volts, check vacuum hose for proper connection, cracks, blockage or disconnection.
- If voltage does not fluctuate 0-12 volts, measure voltage between ground and Green/Black wire terminal of harness at 2500 RPM. If voltage fluctuates 0-12 volts, repair open in Black wire between solenoid and ground.
- If voltage does not fluctuate 0-12 volts, repair open in Green/Black wire between solenoid valve and control unit terminal No. 29. If wire is okay, fault is in ECU control circuit. Go to TROUBLE SHOOTING
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Courtesy of AMERICAN HONDA MOTOR CO., INC.