Please help, fuel rail overpressure....

[bun7575]

Hi guys , so I have a 2014 2.2 , that's been given me fits , failing injectors, fuel pump etc ...
Friday it packed up totally.
Po088d .fuel over pressure...
So I plugged in for scan ..fuel pressure reading 222350 .. or something ridiculous... Engine OFF , sensor unplugged???
So tested the 3 wire rail sensor plug ... I have ground and 2x 5v.
Which to me seems just wrong. My assumption is the signal wire shouldn't be showing 5v when unplugged. Also if I short the signal wire to ground ,,,the fuel pressure reading drops to zero.
So does anyone know,,, what voltage the signal wire should show , unplugged, ignition on?
I'm thinking either ECU is junk , or loom is shorting somewhere, and it's powering the wire through ECU....
I say this because I traced the signal wire back and put a jumper wire in , exact same result...
Any help appreciated,,,, I'm stuck between putting another loom on , or sending ECU for repair???

[Airthies]

Sensors run on 5v
At the sensor you have a
+5v
-0v
Signal return (variable).
I'd need to meter one out to confirm but there's generally 2 ways an ECU detects a return signal.
One way is to have a trace voltage at the input pin.
When the sensor is connected it sees the variable voltage returned from the sensor.
When the sensor is disconnected it has nowhere for this milliamp voltage to go so it reads full 5v.

I'd be unplugging harness at the pcm and pinout the three wires for continuity, and short. To confirm harness integrity first.
You may get what seems like erroneous results if other sensors that share the 5v/0v circuit are still connected.


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[bun7575]

Thanks , pretty much thinking get another loom , not too much money,,,I literally get one day a week at home so I'm trying to get ahead of myself a bit ...
But yeah, Im thinking loom looks a likely candidate now , especially as if I ground the signal wire , the ECU see's it ..