I unplugged the plug from the ECU.

And every sensor notices its not plugged in.

But, again the pressure relief is circuit open

Click image to enlarge

Here is the wiring diagram.

Am I correct, BW to ecu and brown to ?

Thanks for pointing me back here via PM.

Brown/white is ground path back to the ECM. Brown is the 12V out from the ECM, at least that's how I'd interpret the colour codes.
Just a thought.

The plug hasn't got mixed up with the volume control solenoid on the pump has it? Hyundai Ioniq 5 Ultimate. The family car.
2009 Rimini Red SE TD4. Gone.
2006 Tonga Green i6 HSE. Gone.
Audi A5 convertible, my daily driver.
1972 Hillman Avenger GT, the project.

Thanks nodge for getting back to me.

The brown cable is the 12v cable on the sensor plug.
BW is control cable. That has voltage. Around 3.5v I'm not sure if it should or not.

Regarding the plug mix up. 99.9% ure it hasn't. If it had, then I'm guessing my diagnostic scan would flag it straight away.


Is there any fuses or relays that this PCV valve needs?

I've brought another crank sensor. As you never know, it could be that. But I'm assuming the noid light would atleast flash on the injector just incorrect timing I'm guessing.

You mentioned using noid lights.
Are they for coil injectors or piezo injectors?

The the rail pressure control valve is fused (FE11 10A), but on the brown wire, so if you have battery voltage on the brown, the fuse is ok. Hyundai Ioniq 5 Ultimate. The family car.
2009 Rimini Red SE TD4. Gone.
2006 Tonga Green i6 HSE. Gone.
Audi A5 convertible, my daily driver.
1972 Hillman Avenger GT, the project.

IanMetro wrote:

I think that this is a description of the Circuit ( O_T_PCV ) that is indicated as faulty. (From Repair Manual)

Pressure Control Valve (PCV)

[i]The PCV is mounted in the end of the fuel rail (transmission end) and connected to the ECM via the engine harness. The
PCV is a solenoid-operated valve controlled by a 12V PWM signal. The ECM operates the PCV to adjust the fuel pressure
within the fuel rail.

Relieved fuel is directed through the fuel rail leak-off pipe to the fuel filter return circuit. The leak-off
fuel also provides cooling and lubrication for the PCV.
For additional information, refer to: Electronic Engine Controls - 2.2L Diesel (303-14 Electronic Engine Controls - 2.2L
Diesel, Description and Operation).

The PCV is normally open when the solenoid is not energized by the ECM. The resistance value of the PCV solenoid coil is
3.6 ohms at 20°C (68°F).

The PCV is also used by the ECM to provide direct control of the fuel system, in the following situations:

During sudden transient phases in engine speed (suddenly lifting off the accelerator pedal, for example) where VCV
action is not sufficient to affect the supply of fuel to the fuel rail.

To control fuel pressure in the event that the VCV fails.

During the fuel heating period, when supply fuel temperature is less than 40°C (104°F). The VCV is fully opened by
the ECM and the HP pump compresses a maximum quantity of fuel to raise the fuel temperature. The PCV is then
modulated by the ECM to provide leak-off fuel from the fuel rail to the fuel filter return circuit. The fuel is then
recirculated through the fuel filter and back to the HP pump.

When the fuel supply temperature is greater than 70°C (158°F). The PCV is modulated by the ECM to release fuel
rail pressure, subsequently decreasing the fuel temperature to protect the fuel system components. Leak-off fuel
from the fuel rail is directed to the fuel filter return circuit and back to the fuel tank.

During engine shutdown to progressively collapse fuel rail pressure.[/i]

Link explaining how the PWM valve signal is measured.

https://www.picoauto.com/library/automotiv...sch-cdi-3/

 FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 77k+ miles) (MY2015)
Metro in its 11th Year of (Extended) LR Warranty / Full LR Service History
(Expensive, but Trouble/Worry free - hopefully?)

Nodge68 wrote:

You mentioned using noid lights.
Are they for coil injectors or piezo injectors?

The the rail pressure control valve is fused (FE11 10A), but on the brown wire, so if you have battery voltage on the brown, the fuse is ok.

IanMetro wrote:

Link explaining how the PWM valve signal is measured.

https://www.picoauto.com/library/automotiv...sch-cdi-3/

As I my previous post says (quote from Repair Manual)

The PCV is normally open when the solenoid is not energized by the ECM.

The resistance value of the PCV solenoid coil is
3.6 ohms at 20°C (68°F).

So this is the only resistance check (3.6 ohms) that you can do on the disconnected valve, if it is wrong then that's easy, change it.

If you say that your wiring is checking out OK, then you need to find a way of checking that the signal from the ECM, and the duty cycle sent from the ECM is correct, to allow the correct pressure on the fuel rail to start the engine. This would normally be done by using a 'break out cable' allowing you to measure the signal, while the components are connected and operating. The 12v connection via the PCV coil is needed to get an output from the ECM Circuit.
I believe you should be getting a PWM Signal once the ignition is on and start button pressed in preparation of fuel rail pressuring and engine start.

The next step will then depend on whether the ECM is operating (or its inputs from various sensors), but as the code continues to read P009b O_T_PCV I would have a careful look at the connectors (and their pins) as you say the cable is OK. I suppose the transistor (or similar) circuit providing the PWM could be damaged in the ECM, but hopefully not.

No other Checks/Codes seem to rule out shorts etc.

P009B00 Fuel Pressure Relief Control Circuit/Open
Pressure control valve control circuit - open load
Carry out the pinpoint tests associated with this DTC using the manufacturer approved diagnostic system

P009C00 Fuel Pressure Relief Control Circuit Low
Pressure control valve control circuit - short to ground
Carry out the pinpoint tests associated with this DTC using the manufacturer approved diagnostic system

P009D00 Fuel Pressure Relief Control Circuit High
Pressure control valve control circuit - short to power
Carry out the pinpoint tests associated with this DTC using the manufacturer approved diagnostic system

P009E00 Fuel Pressure Relief Control Performance/Stuck Off
Pressure control valve power stage excess temperature
Refer to electrical circuit diagrams and check pressure control valve circuit for high resistance, if
no fault identified install new ECM.
Refer to the new module/component installation note at the top of the DTC Index FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 77k+ miles) (MY2015)
Metro in its 11th Year of (Extended) LR Warranty / Full LR Service History
(Expensive, but Trouble/Worry free - hopefully?)

UPDATE.

Finally, the code is gone..

I thought I'd just try a new loom, and now I have 0 fault codes. And no reduced engine performance on dash.

Thank you all for your help on that matter.

BUT.

Still won't start.

Cranking pressure is 300bar now the relief valve is allowing pressure to build in the rail.

There's fuel getting to the injectors, I'm not confident the injectors are getting power.

It runs on easy start.


I did take a injector out. Safely aimed it away from everything, grounded it and plugged it in.

And turned the engine over. No sprays atoll.

So, progress made. But still at a loss.

The injectors don't need grounding, they have 2 control wires in the plug.

The injectors won't be triggered if the cam sensor or crank sensor don't give a timing pulse. Hyundai Ioniq 5 Ultimate. The family car.
2009 Rimini Red SE TD4. Gone.
2006 Tonga Green i6 HSE. Gone.
Audi A5 convertible, my daily driver.
1972 Hillman Avenger GT, the project.

Cheers nodge.

So, is that a way of testing? I know it's not a professional way, but atleast I know for sure if they fire.

Got a new crank sensor and cam to it

Also, will recheck the timing... I've heard a tooth out can stop injectors firing.

Thanks for update. FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 77k+ miles) (MY2015)
Metro in its 11th Year of (Extended) LR Warranty / Full LR Service History
(Expensive, but Trouble/Worry free - hopefully?)

Jw2000uk wrote:

Cheers nodge.

So, is that a way of testing? I know it's not a professional way, but atleast I know for sure if they fire.

Got a new crank sensor and cam to it

Also, will recheck the timing... I've heard a tooth out can stop injectors firing.