ZD30 engine problems

[thw72]

My 2008 patrol ute has an electrical problem that I am struggling to pin point the cause of. It is displaying a code on my reader P0193 which I am aware could be a number of things. All I can find is when I test the voltage at the fuel pressure sensor (or back at the control module) I am receiving o volts on the positive wire (should be 5 volts) and 5 volts on the signal wire (should be 0.5 to 3.5 volts) this does not change at all. It doesn't matter if the motor is running or not, or if the pressure sensor is connected or not. It is getting frustrating has anyone else come across a similar problem.
cheers

[threedogs]

Yendor might be your man for this problem, do you think it may be an earthing problem?
Have you tried disconnecting battery for 1/2 hour or so. How about the control module relay.
Some swap with the aircon relay to test, all I've got atm

[thw72]

I have tried disconnecting battery for up to seven days but no change I have tried putting extra earths on with no luck my theory was a fault elsewhere in the system was making the ecm do this however I can't find anything that seems wrong, there is no check engine light coming up and no other codes
thanks for your reply

[Yendor]

My 2008 patrol ute has an electrical problem that I am struggling to pin point the cause of. It is displaying a code on my reader P0193 which I am aware could be a number of things. All I can find is when I test the voltage at the fuel pressure sensor (or back at the control module) I am receiving o volts on the positive wire (should be 5 volts) and 5 volts on the signal wire (should be 0.5 to 3.5 volts) this does not change at all. It doesn't matter if the motor is running or not, or if the pressure sensor is connected or not. It is getting frustrating has anyone else come across a similar problem.
cheers

What color wires are you checking for the "positive wire" and the "signal wire"?

Where are you connecting the earth for your multimeter to?

Have you checked for a short to ground on the "positive wire"?

[happygu]

My 2008 patrol ute has an electrical problem that I am struggling to pin point the cause of. It is displaying a code on my reader P0193 which I am aware could be a number of things. All I can find is when I test the voltage at the fuel pressure sensor (or back at the control module) I am receiving o volts on the positive wire (should be 5 volts) and 5 volts on the signal wire (should be 0.5 to 3.5 volts) this does not change at all. It doesn't matter if the motor is running or not, or if the pressure sensor is connected or not. It is getting frustrating has anyone else come across a similar problem.
cheers

Did this happen after you did any other work on the car, or anyone else for that matter?

The connector doesn't normally connect in reverse, but do you have the connector twisted around somehow? This would be best checked by the wire colours ......

[thw72]

I am checking the blue / green stripe as positive terminal 137 on ecm and the white / blue stripe as the signal wire. I have used the battery negative, the chassis and the sensor earth wire (orange / blue stripe term 108) as earthing points for my multimeter all give same result. Also my auto scanner gives a constant 180 000 kpa pressure reading at all times even with out the motor running. I have cut all three wires about 100mm from the ecm to prove there can't be a short anywhere in the wiring harness same test results.

[thw72]

Yes work has been done I apologize in advance if I am babbling on a bit to much here but the problems started over 6 months ago so there is some history that is relevant. firstly I had the sub tank light come on which I ignored for a while. When I decided to look at it I couldn't find what was wrong so run a separate wire to the pump. All was ok until I drove about 15 km with the pump running, I turnt the car off went to restart it about 20 mins later and I had to wind it over for a long time to get it to start once it was running it ran fine though. worried I would burn out the starter motor I then took it to my local mechanic who replaced all 4 injectors, the battery and the starter motor, the sub tank was cleaned out in case of dirty fuel but all was fine. It was starting great after this however when I got about 1 km from the mechanics shop I started getting running problems. the sub tank light came on again and the motor wouldn't rev past 2500-3000 revs and if you kept your foot on the accelerator it would shut the motor down after a while. I took it back to the mechanic, I had him replace the sub tank pump and clear the sub tank light alarm just it case it was related,(no change) he took it to nissan to get them to read the fault codes and they said the injector pump needed replacing, he had the pump tested at two different shops and both said there is nothing wrong with it. he then started replacing parts and swapping parts with other vehicles with no success,( some parts were fuel sensor, air flow sensor ecm & even put old injectors back to try). We got to the point where I was going to have to pay for new parts to try which I decided was a waste without trying to prove them faulty first so decided to bring the car home and go through it myself. On one of my test drives it shut down quicker than normal and when I restarted it was running rough at an idle. I checked the codes and it had throttle / pedal position sensor / switch b circuit low and fuel rail pressure sensor a circuit high input. neither code would reset with my scanner so tried disconnecting the battery theory it took three days with the battery disconnected for the throttle etc code to reset ( has came back up since but can now reset with my scanner) but even after 7 days with battery disconnected the fuel pressure code will not reset. I can get the motor to idle perfectly by reducing the voltage on the positive wire down to approx 1.5 volts using a variable resistor however this does not fix the car. thanks for the question happygtu however I guess you wished you didn't ask now.