a) Disconnect the sensor connector. Connect the "+" of the voltmeter to the connector terminal, "-" of the voltmeter to the ground.
b) turn on the ignition: the voltmeter needle should fluctuate around the 4.5 V mark. If not, remove and check the indicator.
2. Checking the resistance of the pointer. Measure the resistance between terminals TU and E.
- Resistance: about 25 Ohm
If the resistance is not equal to the specified one, replace the indicator.
3. Checking the sensor resistance.
a) Check the change in the sensor resistance when its float moves.
b) Measure the resistance between terminals 1 and 2 of the sensor.
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If the resistance is not equal to the specified one, replace the indicator.
See the source on the internet resource [TOYOTAMAN]