Hi my name is Chris...Hello everyone, before I would like to congratulate you all because I have always read very good information from this forum and I know that you are all helping other people a lot ... I would like to tell you about my case, my fabia (BBZ 1.4 16v) has been giving me problems for a long time and I have not used it for almost 1 year because of this, when turning on it does it perfectly but after 15 min it tries to turn off, if not I keep it accelerated it turns off, for this reason it is impossible to be on the road because it turns off at the red light or at stop, I have a Vag cable and I use it with my version 311.2 and I don't have any DTCs in autoscan the truth is all so confusing, I hope someone has gone through this, additionally my throttle body is clean adjusted ok, my spark plugs are clean, my air filter it's new, my fuel filter is new, my fuel pump is ok, when it turns off if I do an Autoscan there is also no DTC, if it helps friends.

It sounds like your precat lambda probe may be giving inaccurate readings, first you need to check for leaks in all the vacuum lines, mainly the brake servo.

Hello thanks for the answer, a few days ago I changed my precat probe already, I had a short in the probe itself that was already repaired, then I made a tour and the dtc of S1 B1 has not returned, you know where else I should check vacuum leaks apart from servo hose ?? I have my car and I can't use it. Thank you.

Hi @ChrisMG , Ok, this is going to sound a bit like a repeat, but check all the vacuum lines and crankcase ventilation lines, particularly in the places like the lower side of the line to the rocker cover where you can't see it but need to feel, and feel any fabric reinforced lines to see if they collapse when you squeeze them one handed. This means that they have collapsed internally and can stop the engine breathing, just like you describe.

Hello thanks for helping, I have already checked the vacuum lines a little before and I saw something perhaps strange, the hose that goes from the throttle body to the crankcase ventilation housing does not fit completely on one of its sides, it is possible that there  the problem is caused how can I check it?

Thanks really to all of you who are in your precious time thinking about my problem, today I saw something strange in my reviews, exactly when the car is close to shutting down at idle, I hear a strange sound coming from the diaphragm of the vent casing  of the crankcase, there is a small hole in the casing and from there I hear a hum as if it expelled or sucked air I do not know specifically, my ventilation casing was also changed a while ago but I had no results

1 hour ago, ChrisMG said:

Hello thanks for helping, I have already checked the vacuum lines a little before and I saw something perhaps strange, the hose that goes from the throttle body to the crankcase ventilation housing does not fit completely on one of its sides, it is possible that there  the problem is caused how can I check it?

That hose must be airtight at both ends. 

Hi Wino, thanks for your help...is there any other possible vacuum leak that i can check that is to blame for my problem ??  I appreciate your comment

The pipe between EVAP purge valve and intake manifold is another, but from you description of the breather module to intake manifold pipe it sounds like that is the most likely problem.

Also, the metal pipe between EGR valve and intake manifold can be considered a vacuum hose.

Hi Wino and Hello everyone, I have already checked the possible vacuum leaks and I did not find any, vagcom does not show any error even when the car is turned off but I keep it accelerated, I noticed something a little strange and the fans do not turn on when the car reaches the temperature  90 degrees, then apparently my car is overheating I know because the engine feels very hot, but the screen continues to show 90 degrees, could it be a temperature problem and that the ECU protects the engine by turning it off?  all this is very strange, just in case I don't have any errors in my vagcom, my car is a fabia BBZ 1.4 16v 2007 and I am using vagcom version 311 .. thank you all for your kind help

@ChrisMG - That sound plausible, in which case the question is as to whether your fan motors have failed or the thermoswitches that control them have failed "dead".

 

Try giving the fans a direct feed from the battery to the fan and back to earth. If they spin then, the issue is the switches, and if they don't it's the fan motors.

Thanks Ken for your answer ... If it is correct, I just did a test and the connector of the electric fans I made a bridge canceling the thermoswitch that is in the radiator and the fans turn on without problem in both speeds, apparently my thermoswitch is damaged, vagcom  it does not show any error nor does it with the fans, it may be that the problem is generated by the temperature of the motor by not turning on the fans ???

The first thing to check is the relevant fuses. I can look up which those are a little later for you. Another thing to be aware of is that the fans shouldn't come on until the coolant at the thermoswitch is above 96C, and the thermoswitch is after the radiator in flow terms. 

Edited 30 May, 20215 yr by Wino

Thanks Wino, I have checked all the fuses and there are none broken, I have checked them with my multimeter, is there somewhere else I should look for ???

The ones above the battery, including the blade fuses that hide under a plastic cover?

The ones that look like very thin cans?  if all check them and they are correct, disassemble the relay module that handles the ignition of the fans (I send a reference image) and I just tested them and it works, I also checked the voltages on the lines and they have 12v but I have no negative,  I think this comes from the thermoswitch that is on the radiator when the coolant reaches the temperature (you say it must be 96 degrees) definitely when the car is hot there is no negative signal either

The thin strip fuses, yes, but there are also a few more further over, under a cover that unclips. You can see wires going to them, but not the fuses until the cover is removed towards the firewall.

 

Edited 30 May, 20215 yr by Wino

Does the car have air conditioning?

2 minutes ago, Wino said:

Does the car have air conditioning?

Also @ChrisMG - This is relevant to how the fans should operate.

Now I'm on a big screen I can say that if the car has A/C then battery fusebox fuse 9 (5 Amp blade fuse) supplies an ignition switched 12V to the fan control module (pin 1 of the 6-way connector).

Battery fusebox blade fuse number 8 (30 Amp) powers the low speed fans' function via one of the fan control module's relays, in on pin 3 of the 4-way connector, out on pin 2.

Strip fuse number 3 (40A) powers high speed fan function via the other relay inside the module, in on pin 1 out on pin 4 of the 4-way.

 

Earth connections to both fans are directly from the 3-way rectangular connectors nearest the fan motors, to a chassis earth point nearby.

 

 

 

Edited 30 May, 20215 yr by Wino

So now I will check the connections you say, but is it possible that the ECU when detecting that the car is very hot (despite not marking more than 90 degrees on the panel) causes the engine to turn off ???

I don't know if that's possible.

If the engine really did overheat due to fan malfunction or water pump problem, you would lose coolant from the expansion tank I think, as the pressure would cause the cap to release steam. Is that happening?

no there is no coolant leaking from the tank cap, when the coolant is turned off it is quite hot but the expansion tank does not explode

This is a red herring and has nothing to do with why the engine is stalling after fifteen minutes running.

It isn't overheating and the fans are working.

Back on topic you need to change the ECT sensor if you haven't already done so.

thank you Sepulchrave ... no, I haven't changed it yet. I'll do it tomorrow for tests and see if the engine stops shutting down