Operation CHARM: Car repair manuals for everyone.

Engine Speed Switch: Testing and Inspection




1. Connect voltmeter to green/white and black/white wires of electrical connector.
2. Increase engine speed to 2000 RPM, then slowly decrease engine speed and record engine speed at which current flows to circuit, which should be 1400 to 1600 RPM.
3. Slowly increase engine speed and record engine speed at which current does not flow to circuit
4. If difference of two recorded engine speeds is not 50 to 250 RPM, replace engine speed unit.