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Fault diagnosis, brake fluid warning lamp (MIU 2)

Fault diagnosis, brake fluid warning lamp (MIU 2)

Fault symptom

The low brake fluid warning lamp does not light up when the ignition switch is turned to the Drive position.

Diagnostic procedure



1. If the warning lamp lights up when the engine is started but not when the brake fluid level sensor is activated, continue with point 4.

2. If only the charging indicator lamp lights up when the ignition switch is turned to the Drive position, the brake fluid warning lamp is probably faulty. Continue with point 3.

If none of the lamps light up, continue fault diagnosis as described in point 3 on page

3. Change the bulb.

If the lamp still fails to light up when activated, check that the new bulb is OK by fitting it in place of another bulb in the main instrument display panel that does light up.

If the bulb is OK, the fault is probably in the intermediate part of the main instrument display panel which will then have to be changed.

4. Unscrew and lift off the brake fluid reservoir's cap/sensor to check that the sensor's switch contacts close when activated. Then unplug the connector and check whether there is a connection between the switch pins on the level sensor.



5. Connect a jumper lead across the connector pins and see whether the warning lamp in the main instrument display panel lights up.


6. Check whether current is present on pin 1 of the brake fluid sensor's connector by taking a reading across it and a good ground.


If current is present, the fault is in the ground connection. Investigate and take appropriate action.

7. If no voltage is present, check the wiring between the main instrument display panel and the brake fluid level sensor by connecting a BOB to the 56-pin connector behind the main instrument display panel (which should not be connected).


Take a reading to check for an open circuit.