Low coolant light not working

[Sir Brixalot]

Got a leak on pipe to thermostat housing. Changed housing and pipe and clip. Still leaking although I thought it was fixed
The low coolant level light didn’t light up although it does do the pre check on turning the ignition key. Any ideas on how to get the coolant level indicator working. Been through Wiki but internet is very slow so hard to look any further online

[weimarbus]

How empty was the tank?, I think that the contacts extend into the tank around half way, so that the level would need to drop at least half way in the inner tank for the warning light to come on.

[AngeloEvs]

There is a time delay of around 20 to 30 seconds before the warning LED is triggered after coolant falls below the level of the sensor prongs. The most likely cause of the LED failing to trigger is a faulty LSCU module (marked 43 or 42). (It is also possible to put the module in the wrong location in the fuse box given the variations across different models). Without an oscilloscope it is not possible to test the LSCU module, its a case of trying a replacement.

The next likely cause is a non connection between the LSCU output and the temp gauge preventing the trigger pulses actvating the LED circuit.

To test - with ignition on, remove the connector from the level sensor and wait half a minute or so. If no flashing LED then try a replacement module 43 or 42.

[Sir Brixalot]

Thanks the coolant was halfway down the pipe . Relay 43 was in position 4 - should it be in position 3?

[RogerT]

http://syncrosport.com/info/wiring/VW_T ... _SP_DG.pdf" onclick="window.open(this.href);return false;

Yup, it should...

[RogerT]

Fill the coolant tank brim full, and reservoir should be to the low mark. Ignition on, disconnect coolant level sender and wait 20-30 seconds, then coolant level light should start to flash. If not, hmmm.