After reading a lot on the forum for finish with the warning buzzer problem I have not a solution.

Here is the problem:

This is the first time that I started the engine since I brought the car 2 years ago and do a engine repair. I also do a S4 to S5 instrument cluster swap. I test the cables for continuity and all was ok.

Every time that I start the engine or I put the ignition switch into the ON position, the warning buzzer is on. It also flashes on the warning lights "ADD COOLANT" light. It buzzer after around 10 seconds after the the ignition swith is ON or engine started. I know that the buzzer is activated when there is low coolant, or low oil or the RPM limiter is active.

I do the following test following the information on the Workshop Manuals.

For the coolant level warning light:
1. Disconnect the connector from the coolant level sensor.
2. Start the engine and check that the coolant warning light illuminates from 9 to 16 seconds after starting the engine,
3. if there is no illumination, check the fuse, bulb, coolant level sensor unit and wiring harness.

*In this test, the warning light blinks. I think that everything is OK

For the coolant level sensor:
1. Remove the level sensor and connect the connector.
2. With the sensor not grounded to the body, start the engine.
3. After checking that the warning light illuminates, ground the threaded part of the sensor. If the warning light remains illuminates, the sensor is normal. If it does not, the sensor is faulty and should replaced.

*In this test, when I ground the sensor the warning light illuminates. It blinks Everything is OK. The sensor is normal.

Then I go to check the oil level warning light.
1.Disconnect the connector from the oil level sensor.
2. Connect the R/W (red/white cable) terminal wire to a body ground.
3. Start the engine and check that the oil waring light illuminates.
4. If there is no illumination, check the fuse, bulb, and wiring harness.

*In this test, when I ground the cable, the warning light illuminates, but dont blink. Also, if I ground the coolant level sensor the warning light illuminates, but dont blink like they do when the sensor is in his place on the radiator.

I really dont know what can cause this problems and how I can deal with it.

If there is any other test, information or help to solve this problem, I would be very appreciated for your support.

 

You have low coolant


to confirm, unplug the sensor on the top of the radiator, and ground the car side (not the radiator side) of the wire.

You shouldn't get the trigger.

Remember low coolant in the radiator, not low coolant in the coolant overflow tank.

 

Icemark, I top fill the radiator until the coolant came out. Then I test again and the warning light/ buzzer activates. Then I do the test that you write and the problem persist. There is another test to do?

 

Ok, I check the wiring and I found the problem. There was 2 cables behind the instrument panel that touch each other because the old owner removed part of the cover.