Warm up engine to normal operating temperature. Disconnect the upper vacuum hose from the solenoid valve. See Fig 1 . Connect vacuum pump/gauge to upper vacuum hose. If there is intake manifold vacuum when the engine is below 750 rpm, go to next step. If there is no intake manifold vacuum, turn ignition switch OFF and disconnect the 2-pin connector from the solenoid valve. Connect battery positive to terminal A, and battery negative to terminal B of the solenoid valve. See Fig 1 . Start the engine. If there is intake manifold vacuum, solenoid valve is OK, perform the CONTROL UNIT INPUT TEST . If there is no intake manifold vacuum, replace the solenoid valve.
Check for any vacuum when engine speed is above 700 rpm. If there is vacuum, perform the CONTROL UNIT INPUT TEST . If there is no vacuum, solenoid valve and control unit are OK. Go to ENGINE MOUNT DIAPHRAGM ACTUATOR CHECK .

Fig 1: Identifying Engine Mount Control Solenoid Connector Terminals & Vacuum Hoses

Courtesy of AMERICAN HONDA MOTOR CO., INC.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Solenoid Valve Test