Hi All
I've just recently purchased a 2003 TD4 and am having a total nightmare getting it to run. The code on my scanner is P0190 pressure sensor circuit failure. I did a check of the wiring to the sensor on the end of the rail and it seems to be ok but the scanner shows a HP fuel reading of 0. I changed the sensor and still get a 0 reading. There is fuel at the rail, as seen when I cracked a union on an injector with the ignition on. It spurted out but not particularly forcefully. So I turned my attention to the regulator and replaced that as when energised I couldn't hear a distinctive click expected. My replacement arrived and did the same, when given 12V or less. At the regulator I have 3 pins and two give 5V with ignition switched, which I wonder is correct or not.
So could all this be down to the HP fuel pump. I'm reluctant to remove it without checking it's the likely culprit. Any advice would be gratefully received as I'm a bit stuck. Also I only have Rave that covers the NAS freelander and not the TD4, so if anyone has the PDF for that engine I'd like to obtain a copy. Thanks

As the code says fuel sensor circuit failure I'd be looking at the sensor but more important the cable and connector to the sensor, that is known to be problematic.

You will get a hp reading of zero when the engine is not running! As above, corroded connections or broken wire internal to cable is likely.

Thanks for replying. Do you happen to have a circuit diagram for the fuel pressure sensors. I'm struggling to see what the values should be. Would a regulator wiring fault give a similar problem. I've changed the sensor and regulator without any difference.

can't help on values, but maybe you could post what values you are seeing and maybe someone tell if theyre correct.

have a look here https://www.landyzone.co.uk/land-rover/fuel-rail-pressure-sensor-harness-change.154473/
the cable and connectors cause a lot of issues hence why theres an updated harness.

Hi All
I've checked the harness on the pressure sensor (end of rail) and traced it back to the ECU, without finding fault. Does anyone have a wiring diagram that includes the fuel pump actuator. I'm wondering if a duff HP pump could cause the symptoms of non start and put the ML on during cranking for fuel pressure sensor circuit?

Is the wheelarch fuel pump running with ign on?

Hi.
Yes it's running. I'm getting a very odd wooshing noise from the HP fuel pump area for quite a while when turning the ignition on. Is it possible that the HP pump has failed and the P0190 code is registered as the fuel pressure is so low??
Thanks

Just replying to my own thread to say that the P0190 code was due to an earth fault on both the High and Low pressure sensors. After feeding my own earth to both sensors the engine mangement light went straight out. Although the car still does not start. HP fuel is just 50 bar during cranking, so no where near enough. I'm pretty sure the HP pump is kapput as the previous owner didnt address the wiring faults, causing it to run constantly flat out. It also makes a very odd wooshing noise (like air escaping) when the ignition is turned on, so will replace the pump and hopefully it will work!!! The following link provided a lot of info regarding pin outs of relevant sensors, if anyone finds it useful

https://forums.lr4x4.com/topic/95002-td4-starting-problem/

Opps slight mistake in that the fuel pressure is 50PSI during cranking so 3.447 bar!!!