Technical Scudo 2011 2.0 Mjet
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Technical Scudo 2011 2.0 Mjet
Tell us this code
That sounds like a sensible code..
When I had that on a punto diesel I had to change the sensor at the fuel filter..
it did fuel temperature AND water in fuel..same sensor
Argh Im even more confused now the deeper i get into it. The filter housing is a 2 wire connector so if this sensor is a water in fuel and fuel temp sensor how would it do both? Checked the voltage at the connection and i get 12v ign on and earth. I feel im missing something.
@bugsymike may well know the layout of your style of fuel system
Ok progress being made. Found the temp sensor its under the air inlet manifold on the return fuel pipes. Tested the sensor and resistance and it drops as temp rises and vice versa. Unplug sensor and its Its getting 5v until its plugged back in then voltage drops to 1.9v does this mean sensor is goosed?
Keith Spencer
Member
If I'm not mistaken the 1.9v is variable as the resistance of the sensor changes with temperature. So the ECU uses the 1.9v to see the temperature. The 5v reference voltage is perfect, you have proven the changing resistance with temp change, you could belt and brace by measuring the 1.9v change as temp changes.
You need to prove the wire integrity at the ECU. Measure the 1.9v at the ECU plug (back probed).
Your sensor looks good.
Yes i think thats the way to go, trace back to ecu. I presume wires will be the same colour? Hope so.
Hi yes i used Lexia Peugeot diagnostics and fuel temp is a constant 90 degree so something defo adrift. I have 5v at the sensor like u said and a varied resistance as pressure changes. So its leading me to a problem inside the ecu. Ill give it a few more hours of my life then thats it lol.
Keith Spencer
Member
Okay,
To help with your fault finding, you tested the sensor by heating and cooling it and seeing the resistance go up and down, and the sensor is fine. With what you just said that the ECU is showing permanent 90 deg assume the ECU is perfect for a minute and it is obtaining an incorrect voltage, ie not the 1.9v you measured.
You need to decide is it reading a very high voltage, up to 5v (which would indicate a short circuit to a 5v or even a 12v supply wire. Or and this is my guess, it's receiving no or very little voltage well below the 1.9v you measured and the ECU is giving you the max reading it can ie 90 deg.
So when you tested the sensor and you heated it:-
1 If the resistance went down ie the signal wire voltage goes up, then you have a short to live.
2 if the resistance went up ie the signal wire voltage went down, then you are looking for a bad connection in the signal wire (green crusties) or failed completely.
The way to prove either is to check the voltage at the signal wire into the ECU if any difference as above to your reading at sensor you have a fault.
A quick solution then would be to cut the old signal wire and solder and shrink wrap a new wire, must be soldered as every millivolt matters.
If you have an exact accurate sensor voltage at the ECU then yes your ecu is highly suspect.
But don't forget to check the powers and grounds at disconnected ecu plug socket.
A good wiring diagram is pretty much essential at this stage.
Good luck, PS you are doing brilliantly so far, don't give up yet.
Keith Spencer
Member
Ps
I may be slightly confused with the 1.9v from another thread, but the rest is the same.
Keith Spencer
Member
My apologies for the confusion, at the sensor if it's a 3 wire sensor ,1 is 5v reference power supply and 1 is ground to chassis the 3rd is the signal wire to ecu. As the pressure changes the sensor resistance should change and the output signal voltage to the ecu will change accordingly. This voltage should be exactly the same at the ecu. Ie the 1.9v in the other thread.
