Firstly im a new member on this forum and i own a Fabia mk II. Well long story short, basicly my friend owns a newer year of this car and when he turns his car on; a blue light for coolant comes on the dash and goes out after couple km. Well however mine doesnt do that and im wondering which sensor might went out and if it can be  dangerous ? In sense, if engine overheats and the dash doesnt show a red light. Or is this the function of another sensor (thats actually the main question, because otherwise im not fixing it, because this light kinda bothers in the evening)?

 

Well as i mentioned i dont know what is wrong, because when i put my car on OBD theres no errors to show. Im kinda new to this sensor game and i dont even know what to look for. Theres like 2 visible sensors on coolant tube(i guess pressure and temperature) and a couple screws that can be uncrewed(i suppose thats to let air out). I would be really grateful for repair manual for my car, thats in english, if maby some of you guys have it in pdf.

I don't have the relevant owner's manual but a blue coolant light is usually "engine cold". This won't throw a fault code because it's not a fault! If your car doesn't have a temperature gauge, this may mean that you have a dead bulb. Do you get a temperature light on initial switch on, before starting?

3 hours ago, KenONeill said:

I don't have the relevant owner's manual but a blue coolant light is usually "engine cold". This won't throw a fault code because it's not a fault! If your car doesn't have a temperature gauge, this may mean that you have a dead bulb. Do you get a temperature light on initial switch on, before starting?

 

Firstly thanx for answer. Well i will take this video as reference, just for presentation. This is not my car, but it has same armature. Well i get the lights on top along with the red coolant light when i put key on second position, but then the blue one doesnt light up afterwards. 

 

I guess it can be a dead bulb. Im thinking if a  red coolant light shows up on start and temperature sensor  works, there should be a switch that controls, when to light up the blue light or does computer control this? Just thinking before i take everything apart. Because if car somehow got in to short circuit firstly what would went out is switch and then light. Now its just wonders how to find this switch, when i dont even know where temperature sensor is (should it be on coolant hoses or on motor block or else?).

1 hour ago, denis9194 said:

 

Firstly thanx for answer. Well i will take this video as reference, just for presentation. This is not my car, but it has same armature. Well i get the lights on top along with the red coolant light when i put key on second position, but then the blue one doesnt light up afterwards. 

 

I guess it can be a dead bulb. Im thinking if a  red coolant light shows up on start and temperature sensor  works, there should be a switch that controls, when to light up the blue light or does computer control this? Just thinking before i take everything apart. Because if car somehow got in to short circuit firstly what would went out is switch and then light. Now its just wonders how to find this switch, when i dont even know where temperature sensor is (should it be on coolant hoses or on motor block or else?).

I don't know for sure but I'd think these lights are controlled off the usual Coolant Temperature Sensor by the Engine Management System.

 

So we need to test the CTS properly, which means reading the values it's putting to the EMS. That means you need to download VCDS Lite (free) and buy a decent quality OBD2 cable (how well the cable is attached to the connectors is vital). After the car has been standing for several hours, look for an engine temperature about the same as ambient. If the engine is hotter than that, the CTS is probably putting out a "too hot" reading, and if they're the same then it's probably the bulb.

 

If it's the bulb, just remember to keep the revs down to about half of max for the first 5 minutes driving.

Well i just went outside and checked as you suggested. Well thermometer in ambient in shadow is about 20 degrees celzius and when i connected car on OBD and checked CTS sensor of coolant it reads 14 degrees. The car is in shadow as thermometer is. Well temperatures arent showing the same --> is this good or not?. When i will take a car for a ride, i will connect it, so i can see if CTS is working properly.

 

By all thinking if temperaure says 14 degrees, i should get cold engine light anyways if sensor works properly or not.

A thermometer in "general shadow" will read higher than one that's "properly shaded" (Source SCE Geography Alternative syllabus O grade), so I'd say that the thermometer and CTS are reading effectively the same (and the CTS is cooler anyway). I'm afraid it looks like the issue is the bulb.

So do you maby know what i need to take apart to get to this lights? Probably the whole panel with radio to get to speedometer. Or is it any easier way to take out speedometer. And probably the light is LED and is integrated in circut, what makes things even more complicated. Probably im gonna leave stuff as is. I got my water pump and belts changed anyways, so there is low possibility anything could go wrong

@denis9194 Yes, I'm afraid that fixing the tell tail will mean dismantling the fascia, and I've no idea how to do that, or whether it's a bulb or LED.