1. Checking the indicator.
A) Disconnect the connector from the sensor-switch. Short-circuit terminals 1 and 2 of the connector on the wiring side.
b) Start the engine: the indicator should light up. If the indicator does not light up, then check the indicator lamp.
2. Checking the sensor-switch.
A) Apply a vacuum of 3.9±0.5 kPa or greater. Check for continuity between sensor connector terminals.
b) Check for continuity between the sensor connector terminals when the vacuum is released.