1. Checking the operation of the indicator lamp
A) Disconnect the vacuum sensor connector. Ground terminal 1 of the connector.
b) start the engine: the indicator lamp should be on.
If not, remove and check the lamp.
2. Checking the operation of the vacuum sensor.
A) check the absence of conductivity between the outputs of the sensor in the absence of vacuum on it.
b) create a vacuum of 29.4 + 3.7 mm Hg on the sensor, check for conductivity between the sensor leads.