Technical Car won't turn off

[ArcticStilo]

So my fiat stilo 1.6 16v 2002 has developed a new issue/issues. It wont start if i dont first take the battery terminal off, then after starting it wont turn off even taking the key out or taking the battery terminals off!!
its giving me codes
u1706, u1700, P0638, u1600, p1687, p0335
All fuses from the engine bay are ok.
Literaly all help or crazy ideas would be much apreciated because i am running out of ideas.
I Currently have the enginebay fuse box on the table.

 

[varesecrazy]

I've not had a Stilo..

But search D4 on here for Lots of random electrical problem information

 

[ArcticStilo]

I've not had a Stilo..

But search D4 on here for Lots of random electrical problem information

What could be even wrong in it?

 

[aschiuta]

.... it wont turn off even taking the key out or taking the battery terminals off!!

And how do you stop the engine?

 

[The Panda Nut]

Its probably a faulty key switch, but there are a few possibilities. I have experienced this many years ago. You can of course stall the car by selecting top gear , keeping your foot on the brake and letting the clutch up.

 

[ArcticStilo]

And how do you stop the engine?

i dump the clutch while being in a high gear while holding brake.

 

[ArcticStilo]

Its probably a faulty key switch, but there are a few possibilities. I have experienced this many years ago. You can of course stall the car by selecting top gear , keeping your foot on the brake and letting the clutch up.

so a broken ignition barrel. Have you got any other ideas?

 

[The Panda Nut]

i dump the clutch while being in a high gear while holding brake.

Yep that will stop it. But release gently asit will put less strain in the clutch.

so a broken ignition barrel. Have you got any other ideas?

The whole car is ECU conmtrolled so it could be a fault there or in the wiring. I dont know anything about these things I am sorry. I always think back to the pre ecu days as basic mechanical faults are easier to identify and probably more likely. I am sure other more expert people will be along to advise on the electronics aspects

 

[aschiuta]

i dump the clutch while being in a high gear while holding brake.

Sorry but this is weird thing. Your engine is gasoline. You need sparks to ignite. If you disconnect battery = no sparks.
Not enough pressure in cylinders block for autoignite like diesel engine. So , I think in fact, you dont really disconnect voltage when remove the red wire from battery. The alternator still provide voltage for the machine electronics is the logical explanation. So look in this area.

 

[ArcticStilo]

I've not had a Stilo..

But search D4 on here for Lots of random electrical problem information

most likely was this. i cleaned it with electrical cleaner and let it dry for a day. also went trough the fuse box with the same stuff and dried it with a hairdryer

 

[ArcticStilo]

Yep that will stop it. But release gently asit will put less strain in the clutch.

The whole car is ECU conmtrolled so it could be a fault there or in the wiring. I dont know anything about these things I am sorry. I always think back to the pre ecu days as basic mechanical faults are easier to identify and probably more likely. I am sure other more expert people will be along to advise on the electronics aspects

yeah but in my experience with this badboy every problem has been either an electrical or wiring problem so far, only had to replace one wheel bearing for inspection wich hasent been an electrical problem. fiats carry a massive stigma here in Finland for electrical faults. is it our horrible weather or something i dont know what.

 

[ArcticStilo]

Sorry but this is weird thing. Your engine is gasoline. You need sparks to ignite. If you disconnect battery = no sparks.
Not enough pressure in cylinders block for autoignite like diesel engine. So , I think in fact, you dont really disconnect voltage when remove the red wire from battery. The alternator still provide voltage for the machine electronics is the logical explanation. So look in this area.

Here is a video shot by my GF of her having the keys and me taking the terminals off while the car runs.

 

[aschiuta]

Here is a video shot by my GF of her having the keys and me taking the terminals off while the car runs.

Yes the thick red cables are together. As long as the alternator rotates, it provides electricity for the car.
Probably electrical contacts on key = H1 are short-circuited and even you remove the key, the ECU = M10 are supplied with voltage at pin 29. M10 drives the injectors and spark plugs coils. Relay T9 feed with voltage the injectors and coils and others components. On pictures are the voltage for normal operation. When the key is off or removed there must be no voltage on F16 pins.

 

[ArcticStilo]

Yes the thick red cables are together. As long as the alternator rotates, it provides electricity for the car.
Probably electrical contacts on key = H1 are short-circuited and even you remove the key, the ECU = M10 are supplied with voltage at pin 29. M10 drives the injectors and spark plugs coils. Relay T9 feed with voltage the injectors and coils and others components. On pictures are the voltage for normal operation. When the key is off or removed there must be no voltage on F16 pins.

Thank you! Thats some intresting stuff even though the problem was resolved by fidling with the D4 connector this time.
I have always before dealt with cars that run the circuit trought the battery.

 

[AndyRKett]

Sorry but this is weird thing. Your engine is gasoline. You need sparks to ignite. If you disconnect battery = no sparks.
Not enough pressure in cylinders block for autoignite like diesel engine. So , I think in fact, you dont really disconnect voltage when remove the red wire from battery. The alternator still provide voltage for the machine electronics is the logical explanation. So look in this area.

You know that alternator on the side of an engine? The thing that makes electricity to charge the battery?


Yes you can very easily disconnect the battery on a car and it will keep running, though the battery acts as a nice big capacitor to keep the output of the alternator nice and stable where as without an battery you can get more obvious fluctuations in the voltage.