Technical Another Stilo preheat question

[lxrose]

Hi to all Fiat owners,

I am an old Fiat Stilo 1.9 JTD MultiWagon owner and I am a reader of this site when I need some information. This time I registered, because I didn't find the answer to my question. (Anybody here still own a Stilo? )
So last year I had my car mechanic replace all the glow plugs because of the preheat fault warning, but the problem is still there. I verified all the related fuses and the relay (it activates, if I apply 12V to it). What I cannot find and don't know how to check is the O20 preheat resistor, which must be somewhere inside the engine close to the diesel pipes. I have a guess, but I am not dare enough to remove the plug and it is not so easy to reach either. Can anyone post a picture of the related part (in its location) and some instructions how to be able to measure if it is functioning correctly. I mean where to put the wires of my multimeter where it is easy to measure if this part is broken? I have basic troubleshooting skills and some electric background too.

Thanks for everyone who replies.
lxrose

 

[Davren]

According to the Stilo eLearn workshop manual, O20 preheat resistor is a diesel fuel preheater on the side of the fuel filter head. It's a preheator, not a sensor.

Item 16 in the diagram below.

1 - Fuel tank
2 - Submerged fuel assembly complete with level gauge control
3 - Fuel filler pipe
4 - Reflux pipe
5 - Fuel filter element
6 - Water in fuel filter sensor
7 - Pressure pump
8 - High pressure pipes
9 - Single fuel manifold pipe
10 – Injectors
11 - Pipe from injectors to fuel return manifold pipe
12 - Fuel return manifold
13 - Pressure regulator
14 - Fuel temperature sensor
15 - Fuel pressure sensor
16 - Fuel heater
17 - Inertia switch

 

[lxrose]

According to the Stilo eLearn workshop manual, O20 preheat resistor is a diesel fuel preheater on the side of the fuel filter head. It's a preheator, not a sensor.

Item 16 in the diagram below.

1 - Fuel tank
2 - Submerged fuel assembly complete with level gauge control
3 - Fuel filler pipe
4 - Reflux pipe
5 - Fuel filter element
6 - Water in fuel filter sensor
7 - Pressure pump
8 - High pressure pipes
9 - Single fuel manifold pipe
10 – Injectors
11 - Pipe from injectors to fuel return manifold pipe
12 - Fuel return manifold
13 - Pressure regulator
14 - Fuel temperature sensor
15 - Fuel pressure sensor
16 - Fuel heater
17 - Inertia switch

View attachment 429885

Hi Davren,

Thank you for your reply. I am going to check this location. Do you know if this is the resistor that is feed by the relay T19 or is it a different one controlled by another circuit?

Cheers,
Sándor

 

[Davren]

Hi Davren,

Thank you for your reply. I am going to check this location. Do you know if this is the resistor that is feed by the relay T19 or is it a different one controlled by another circuit?

Cheers,
Sándor

Yes, O20 gets a power supply from relay T19 in the engine compartment fuse box B1.

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3360997 - E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT - Wiring diagram​

Wiring diagram​

 

[lxrose]

Yes, O20 gets a power supply from relay T19 in the engine compartment fuse box B1.

Thanks for confirming. I will measure this resistor on the weekend. Hopefully I will find out something. I would like to fix it before winter, but things are going slowly on my side.