P1210 fuel pressure regulator fault

[darbuck]

Hi all, I have started a new thread for this as it's a new problem. The C5 is throwing code P1210 open circuit pressure regulator. I plan to pull the regulator over the next few days to test it.There is absolutely no fuel pressure and it's reading 96ma of current. She briefly ran on easy start but doesn't sound great hopefully when I get the fueling problem sorted. How likely is it the regulator itself has failed given the code? What current should I be seeing? Can anyone give me the expected values associated with the regulator?

[KennyW]

Darren,

HAVE A LOOK AT THIS YOU TUBE VIDEO



Kenny

[darbuck]

Will do thanks Kenny

[darbuck]

Hi all I tried again this evening, I have no power to the regulator as far as I can make out. The regulator activated when bench tested but I have ordered a new one on the off chance it's iffy. I need to figure out how it's wired back to the ECU.

[Rhothgar]

Ideally, you should scope the fuel pressure regulator if you have the kit because it is switch using pulse width modulation. On a Lexia, the duty cycle should be around 17-19% at idle.

As you say, if you are not building pressure then it could be either the regulator or the fuel pressure sensor itself reporting incorrect pressures.

Trying to recall if the issue I had with my Xantia HDi was caused by the double relay. A quick search of the forum for Picotech should find my post.

[darbuck]

Thanks Rhotgar, I have a cheap hantek scope it does what I need it to do and I have a diagbox so will have a look tonight after work hopefully. I did have a look at the wiring last night but I would need to unpluck the loom to back trace it to find the correct pinout. Mark did provide me with the wiring diagram but I couldn't find the wiring number on the cables. I will post up my findings after I run tests. I think I saw a reference to high pressure the other evening on diagbox so maybe it's the sensor but I will double check first.

[darbuck]

Hi Rhothgar, the regulator at a very rough idle is 50 to 60% now before she shudders and dies and fuel pressure maxed out at 2000 bar very briefly but didn't seem to be able to maintain it according to lexia diagbox it was dropping to between 300 and 700 bar not sufficient pressure I think. Injectors all at -1.96. so they're not opening properly I imagine because of the parameters. They actuate fine and no injector fault codes. What do you think? Regulator?

The exhaust temperature sensor is causing a fault code would this have a bearing on the values.

[KennyW]

Darren,

I've looked at the wiring diagram Marc provided and can't see the regulator (1322) anywhere. So I checked my vehicle wiring diagram and no regulator shown there.

I know the regulator is attached to the pump just like yours. Is the wiring for the pump run through the regulator or separate ?

I'm going out to finish off refitting the wheel hub after changing the bearing and I'll have look.

Anybody have any thoughts or wise words.

Kenny

[darbuck]

Hi Kenny,
The wiring for the pump shown in the diagram is the regulator wiring there are two electronic units on the pump the regulator and the fuel temperature sensor the pump itself is mechanical so no wiring. The regulator solenoid is 1208 on the diagram and 1221 is the fuel temperature sensor. I am pretty much convinced it's the regulator given it can't maintain fuel pressure and shows control is attempted by the ECU but the regulator is adjusting but can't meet duty. I am also going to replace the exhaust temperature sensor because the harness was damaged when I removed the engine and I now have a related fault code. Best of luck with the bearing by the way

[Rhothgar]

Darren,

I've looked at the wiring diagram Marc provided and can't see the regulator (1322) anywhere.

Kenny

Where is the diagram Marc kindly provided?

[Rhothgar]

Hi Rhothgar, the regulator at a very rough idle is 50 to 60% now before she shudders and dies and fuel pressure maxed out at 2000 bar very briefly but didn't seem to be able to maintain it according to lexia diagbox it was dropping to between 300 and 700 bar not sufficient pressure I think. Injectors all at -1.96. so they're not opening properly I imagine because of the parameters. They actuate fine and no injector fault codes. What do you think? Regulator?

The exhaust temperature sensor is causing a fault code would this have a bearing on the values.

@darbuck

Hopefully, @wheeler will have some constructive comments on what I say below.

Which ECU do you have? The 88 pin EDC15C2?

The P1210 code you gave actually means:-
Injector Control Pressure Above Expected Level

When I check for codes now online, I would type for this code eg P1210 ODB-II (and perhaps Citroen after it). OBD-II is a protocol so the codes should be standardised across all manufacturers.

So this figures - you have let's say 55% open cycle. That means the pressure is sky high. The car needs 300 bar to start so this is why it starts but then builds pressure very rapidly and dies.

This doesn't mean that the FPR is faulty per se. The signal it is receiving is telling it, it needs to open to 55% and it may simply be responding to that command. The Fuel Pressure Sensor on the other hand is quite hard to scope. It's in a horrible location.

This is the troubleshooting process I now follow because you do not go swapping parts that do not need replacing.

1) Check for common issues and look for links between the fault code you have and other components that come from the same loom or wiring splice. I have an intermittent issue on my HDi at the moment which I will post about soon and what steps I am taking to diagnose it. I have code P0246 Turbocharger Pressure Solenoid High. Intermittent issues are a nightmare to troubleshoot. So for this, I have checked the electrovalves and they seem to be behaving correctly. The one thing I haven't checked is the wiring for intermittent shorts. But when I get the chance I will be checking splice E123 - The reason because I also had a jerky speedo one day last week after bending the wiring out of the way at the ECU to do the cambelt. When I pressed the wiring again, it resolved the speedo issue.

2) Check Fuses.

3) Check for basic voltages at component with Key On Engine Off. Are they what they should be or are they out of spec? Actuators tend to be 12V and sensors tend to be 5V.

4) Check Wiring (I now always do a thorough check such as this when I have want to rule out the free repair options first - I don't tend to go swapping components willy-nilly. It's too expensive and may not solve issue).
Note - wiring should be load tested to ensure it can carry current. Ensure you disconnect at ECU and the component for load testing so you don't end up doing something you shouldn't. Checking continuity is only a basic test and can give false confidence. For example, you can a Citroen wire with 17 strands of 0.1 mm cross section, 16 of them could be corroded and high resistance, you could then touch, miraculously, each end of that good wire with your DMM and get a sound continuity reading. Load testing checks whether the continuity is good across all strands.

5) Check component. You don't need to scope the FPR as it is reporting it is 55%. This could actually mean that the fuel pressure sensor is faulty and reporting to the ECU that it needs more pressure and the ECU then tells the FPR to stay open for longer to build pressure.

I think the wiring to your FPR is probably fine because otherwise the FPR would not be actuating. It clearly is as the car starts and then stops.

It could be that the double relay at the ECU is faulty. This is a common fault. I'll post a link to my woes on my HDi or you can search it if you haven't done already. I was learning diagnostics back then and still am always looking to learn when I have the time. I have a very good friend who I can bounce off. He feeds me titbits and gets me thinking about things and questions me. Sometimes I think he does it to put a seed of doubt in my mind so I think harder about it and therefore more logically. Conversations with him can take hours but it's really useful. He's full of anecdotes.

One quote he said to me the other day, "If you change a part and it doesn't fix the issue, what would you do next?". Awaits my response and continues, "Well do that before you change the part!". Again, it's all to down to not condemning a part before you have checked the most logical stuff first. Scan tools are fine. Understanding what they are telling you is an entirely different matter. It should be a process of elimination.

Be VERY careful if you decide the FPR needs changing. I managed to snap the mounting bolt inside the pump and had to dremel a slot in it. You need to be squeaky clean at all times and don't touch the tip of the FPR.

I've included a check sheet for some components and a snapshot of the wiring diagram I have.

You will note that Pin 1 of FPR 1322 goes to Pin 50 of the ECU. This will be its signal wire. It gets its power supply from Pin 9 on 1304 Double Relay through Pin 2.

I am just wondering that if the double relay is stuck, would it power the fans at ignition on? Maybe not. I am not sure.

Checks Pins 86, 1 and 29 at the ECU with Ignition Off.

Pin 86 - 11-14V
Pin 1 - 0V
Pin 29 - 0V

Pin 2 of FPR (Pink wire) - 0V

With ignition on
Pin 86 - 0-1V
Pin 1 - 11-14V
Pin 29 - 11-14V

If the above voltage checks at ECU and FPR don't check out then the double relay is faulty I would say.

Sorry but I don't seem to be able to send all photos from my phone to my desktop at the moment. There seems to be an issue and I need to crack on with my work day.

Hopefully, this will be of some help to you.

[Rhothgar]

Hi Kenny,
The wiring for the pump shown in the diagram is the regulator wiring there are two electronic units on the pump the regulator and the fuel temperature sensor the pump itself is mechanical so no wiring. The regulator solenoid is 1208 on the diagram and 1221 is the fuel temperature sensor. I am pretty much convinced it's the regulator given it can't maintain fuel pressure and shows control is attempted by the ECU but the regulator is adjusting but can't meet duty. I am also going to replace the exhaust temperature sensor because the harness was damaged when I removed the engine and I now have a related fault code. Best of luck with the bearing by the way

I am assuming that this is on your C5 110bhp 2.0HDi. I hope so otherwise I've wasted a good 1.5 hours researching and prepping my previous post.

I'm confused because you say above the the pump is mechanical. If we're talking about your 110 HDi then it's controlled by the ECU and the fuel pressure regulator. A mechanical pump does not have a fuel pressure regulator!

You say the FPR cannot meet duty. Well it is otherwise you would forever cranking the engine to build enough pressure for it to MAYBE start if you're lucky. You'll of course have read my post above before this anyway no doubt but the issue is it is on for too long and building up excessive pressure according to the 2000 bar you reported.

[GiveMeABreak]

Correct, there is no 1322 Fuel Pressure Regulator component on these engines.

Also please remember that Kenny has a DW10CTED4, Darren has the earlier DW10BTED4 and Roger has a DW10ATED - all completely different engines by comparison and have been through many evolutions and developments so chalk and cheese on many aspects and this can cause confusion.

For a start, here are some differences between the DW10BTED4 and DW10CTED4

Special features: DW10CTED4 engine

• 4 cylinders 16 valves with twin overhead camshafts, driven by toothed belt.
• An inlet manifold incorporated into the cylinder head cover.
• A vacuum reserve incorporated in the inlet manifold.
• An exhaust manifold located on the rear of the engine.
• An oxidising catalytic converter mounted directly on the turbocharger outlet.
• Catalytic converter/monobloc particle emission filter assembly.
• A variable geometry turbocharger, water-cooled.
• An air/air heat exchanger (cooling of the turbocharged air).
• A coolant pump driven by the timing belt.
• Variable-flow oil pump.
• 1Direct injection.
• An exhaust gas recycling device (EGR).
• An electric EGR electrovalve.
• A turbo pressure regulation electrovalve.
• A "vacuum" low pressure circuit.

Modifications (In relation to the DW10BTED4 engine)
Components:

• New integral engine top (HMI)
• Electric exhaust gas recirculation valve
• Exhaust gas recycling (EGR) heat exchanger
• Pneumatic exhaust gas recycling heat exchanger bypass flap
• Exhaust gas recycling (EGR) with exchanger and by-pass at the front instead of at the rear on the DW10BTED4 engine ( make VALEO)
• Exhaust gas recycling module (Valve and cooler cannot be separated)
• Cylinder head with new combustion chamber (Type ECCS identical to the DW12BTED4 engine)
• Variable flow oil pump
• Variable geometry turbocharger without turbo pressure regulation valve (HTT)
• Delphi 1.5 diesel injection system with high pressure circuit to 2000 bars

As I'm confused with all the contributions as to what is required, here is the fuel injection circuit for Darbuck's Vehicle (DW10BTED4):

Key:
A = Fuel tank return circuit
B = Low pressure fuel circuit (negative pressure)
C = Fuel high pressure circuit

Marking	Description	Part number in the electrical diagrams
1	Fuel high pressure common injection rail	-
2	Diesel injectors with solenoid valve (electrohydraulic)	1131 - 1132 - 1133 - 1134
3	Fuel return pipes	-
4	Venturi incorporated in the high pressure pump	-
5	Transfer pump (pre-supply)	-
6	Low pressure actuator (IMV) (Flow regulator)	1208
7	Fuel temperature sensor (Fuel temperature in the transfer pressure chamber)	1221
8	high pressure fuel pump	-
9	Manual fuel primer pump	-
10	Fuel cooler	-
11	Fuel tank	-
12	Fuel filter with integrated diesel fuel heater	1276
13	High pressure fuel sensor	1321

(IMV: Intel Metering Valve).

Special features:

• Fuel supply circuit with negative pressure: Induction by means of a transfer pump incorporated in the fuel high pressure pump
• The low pressure actuator (IMV) is a flow regulator
• The high pressure fuel pump incorporates a venturi block, the injector return passes via the high pressure pump

P1210 Fault Code

Fault Code:	P1210
Description of Fault:	Fuel flow regulation electrovalve: Open circuit. Open circuit on the fuel flow regulator control for 500 ms
Conditions for Fault to clear:	Driving for 5 minutes
Downgrade Modes whilst Fault is active:	Deactivation of processing of the accelerometry Deactivation of the speed limiter Deactivation speed limiter until the next time the ignition is switched on Deactivation of the cruise control Deactivation cruise control until the next time the ignition is switched on Request for Delayed Engine Stop Deactivation of the pilot and post-injection injections Deactivation of the detection of loop difference on the fuel flow rate regulator Deactivation of this compensation strategy of the injectors postinjection to postinjection Deactivation of injection compensations The ECU limits the fuel flow Deactivation of the rail pressure faults
Symptoms:	Engine hesitating, cutting out Noise Starting problem Smoke from the exhaust Lack of power
Suspect Areas:	Electrical harness Connections High pressure pump Engine ECU

[Rhothgar]

Marc. 1208 looks to be the fuel pressure regulator
except they have it down as an IMV. Just wondering if it works in reverse to a FPR.

Are there any figures for its duty cycle at idle anywhere and where can I find the wiring diagram for his car please?

Luckily my general principles remain so all is not lost.

[GiveMeABreak]

This is the Injection Diagram for Darbuck's DW10BTED4