Technical Fault code P0190 and P1620

[Borsini]

Hi guys!

I have a problem with a 2006, Fiat Punto, 1.2 Natural Power (LPG/petrol), ZFA18800000910182

The car/engine is running fine but it failed MOT because of a P0190 fault code.
There is a Pending fault code P1620 as well.

I've checked the ECU (fiat 51815709) near the battery. Both connectors are cleaned even they looked fine. I've opened the ECU and visually checked the PCB and soldering. Everything seems ok.
I've cleaned the contacts on the air vacuum valve sensor/purge valve (CK.0013770.C)without any result.

Is it possible to test the valve in an easy way?

Does anybody have an idea what might be the problem/reason for the P0190 fault code?

I would be thankful for any hint or ideas!

 

[fingers99]

Do a Google for P0190 obd. My guess is it has nothing whatsoever to do with the purge valve.

Sweden is a strange place, but do they normally fail cars simply on an OBD error?

 

[Borsini]

Yes, Sweden is a strange place and "yes" they fail cars on an OBD error.

I've tried Google search, but I've not found anything which makes sense in my case.

 

[fingers99]

I get:

P0190 - Fuel Rail Pressure Sensor Circuit Malfunction

Read more: http://engine-codes.com/p0190.html#ixzz35g4w0edW

The pending code is a warning that a service is due.

 

[s and b]

from poland

P0190 "tank pressure sensor power supply (Terminal) fuel-vulnerability"

maybe a garage that repairs lpg systems could help or your dealer?

 

[JLenno]

Hi,

P0190, It could be many things with the fuel;

Fuel rail pressure sensor, vacuum leak, Wrong fuel pressure ( low or high ) They are about all i can think of..i've seen this code before and it was a pressure sensor.

 

[fingers99]

Gotcha. Dual fuel? Or is it?

 

[Ziggy122]

Gotcha. Dual fuel? Or is it?

He did say at top Petrol / LPG

So yea

Autodata lists the codes as

P0190 = Fuel rail pressure (FRP) sensor - circuit malfunction
Causes - Wiring, FRP sensor, ECU

a little google for the other code comes up with this

P1620 – OBD2 Code for Fiat -Error in ECU gas Error



Somewhat vague, but a sneaking suspicion that these 2 error codes are related

I'd be tempted to clear the error codes and bung it back in
UNLESS its a perminant fault that rediagnoses after a few mins of running


Ziggy

 

[fingers99]

He did say at top Petrol / LPG

Sure, but that could relate -- it's a Swedish car -- to the taxation class.

 

[Borsini]

Fingers99: It is dual fuel. There is a switch beside the steering wheel for selecting LPG or petrol.

Ziggy122: I've tried to erase the fault codes but they are back as soon as I'm turning the ignition key to "ON" (position 2).

 

[Borsini]

Does anybody know if the fuel rail pressure sensor an integral part of the fuel pump assembly located In the fuel tank, or?

 

[a1ant]

Hi and Welcome to the forum :wave:

There is no FRP sensor as such. On the LPG versions there is a fuel pressure sensor on the gas regulator valve on the left hand side of the engine bay.

Is the LPG level indicator functioning correctly?
Does the car switch to LPG correctly and then run ok in LPG mode?

Alan

 

[Borsini]

Hi a1ant!
Thank you for your reply!
I have newer tried to run it on LPG. This morning I filled it with liquid gas for the first time.
The LPG level indicator is not working correctly. Only one out of 5 LEDs is on until I start the engine. It does not switch to LPG or run on LPG. It seems like the reason for the fault codes is in the LPG system.
I located the gas regulator valve (Keller PA-22M-80703.12), removed it and cleaned the contacts. Put it back and started the car. Same result as before.
I measured the voltage on the 3 wires to the valve connector:
Blue/Red: 0V ground (Checked the continuity to ground).
Blue/Green: 0,4V (I think this might be the problem) Should be 0,5-4,5V , or am I wrong ?
Red/Green: 4,8V (supply)

 

[a1ant]

Hi,

With the ignition at MAR and the engine OFF... if you press the button for the LPG does the yellow light go out and the Green LPG light come on?

Also, when you say only one of the LED lights are on, are you referring to the 5 LED lights across the top of the LPG control pannel?

With regards to testing the pressure sensor the, the graph below will give you an indication of what sort of signal voltage you are looking for.



WARNING - NOW YOU HAVE FILLED YOU LPG TANK IT IS UNDER HIGH PRESSURE! be careful and check before undoing anything that it is not under pressure. For example, the pressure sensor is on the live side of the circuit.

Alan

 

[Borsini]

The yellow light go out and the Green LPG light does NOT come on.
And, "yes" I'm referring to the 5 LED lights across the top of the LPG control panel.

There is a open/close valve near the LPG tank, at the back of the car. I closed it before I removed the pressure sensor.

 

[a1ant]

Hi mate,

Sorry I didn't mean to sound patronising with regards to the warning, it sounds like you know what your doing anyway, it's more for people who may read this thread in the future and think they can simply remove the pressure sensor, and then have it shot in their face at 15bar!!

The sensor on the pressure regulator is the only one on the system that provides the pressure to the control unit, so it does look like it may be at fault if the gauge is still reading empty.

Have you also checked the connections to the LPG control unit?

Alan

 

[Borsini]

No problem with the warning! I totally agree, it is better with a warning than a sensor shot straight between my eyes
I've only checked the ECU connections on the unit close to the battery and the ECU fitted to the back of the throttle housing .
Where can I find the LPG control unit?
Do you think it would be possible to simulate the pressure sensor?
Ex. connecting the 5V input to the 0,5-4,5V output through diodes in order to lower the voltage to let say 4V.

 

[s and b]

15 bar in your blood and your dead
please refer to my post where you refer to someone who understands the problem here
i might take risks at work but trust me here i put safety first so thus threw away my ham sandwich at 1.01pm prompt this aft



lpg scares me

 

[oldhammer]

DONT play with Lpg unless your clued up on it.
i know someone who was playing with lpg on a pontiac firebird..yes you can understand why lpg on this car..something like 8mpg on petrol,

anyhow..car and garage ended up blowed up..

 

[a1ant]

Hi,

Yes the control unit next to the battery is the LPG control unit. I must advise you that if you have removed the pressure sensor, to test it carefully for leaks once refitted before re-commisioning the system. You dont want LPG leaking in your engine bay.

please refer to my post where you refer to someone who understands the problem here

I have only advised basic functional and electrical testing of the system.

Alan