NOTE: Perform this test on hot engine. Test is for Accord and Prelude models only.

Ground coil secondary wire to prevent engine from starting. Turn ignition to "START" position. Throttle controller arm should retract when engine is cranked. If controller operates, cranking solenoid valve system is okay.
If controller does not operate, check for voltage at cranking solenoid valve. Using voltmeter positive test lead, probe control unit connector Blue/Red wire (Accord models) or Black/White wire (Prelude models). Ground voltmeter negative test lead. If no voltage is present, check wiring and fuse.
If voltage is present, disconnect hose between cranking solenoid valve and check valve at solenoid valve. Check for vacuum while cranking engine.
Vacuum should be present with ignition switch turned to "START" position. If vacuum is present, replace cranking solenoid valve and retest. If there is no vacuum, check vacuum line for leaks or blockage. If vacuum lines are okay, replace check valve and retest.

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

Cranking Solenoid Valve