Fuel Pressure Control Valve Error

[ca2n]

Originally Posted by Roy V70 850

Well, it looks like I spoke too soon. It wasn't the easy option of just being the connection after all.

Took it for 1/2 hour drive, all was well until I put my foot down to accelerate up a hill. The "ENGINE SERVICE REQUIRED URGENT" message came back on. I checked codes with the icarsoft, which came up with rail pressure too low.(not the ctrl valve this time).

Tried this 2 or 3 times on the same road, the ctrl valve fault came up once. I was monitoring the rail pressure and ctrl valve current at the time.

The fault can't be repeated just revving the engine past 2.5k, it appears to only happen whilst under load.

The question is, am I looking at a new ctrl valve, a new pump or the pressure sensor.

Any advice would be much appreciated.

----------------------------
V70 D5 2004 163bph 160k

Hi,

Based on my very limited experience, it seems that insufficient fuel is getting to the HP pump.

Can you verify that the in-tank electric pump is working as it should? I have a similar D5 163 and a similar situation has presented itself when flooring the accelerator pedal with low fuel (less than 1/4 me thinks) in the tank.

Either that and/or a clogged fuel filter.

Hope this helps and good luck!

[Roy V70 850]

Originally Posted by ca2n

Hi,

Based on my very limited experience, it seems that insufficient fuel is getting to the HP pump.

Can you verify that the in-tank electric pump is working as it should? I have a similar D5 163 and a similar situation has presented itself when flooring the accelerator pedal with low fuel (less than 1/4 me thinks) in the tank.

Either that and/or a clogged fuel filter.

Hope this helps and good luck!

The fuel gauge is at approx 1/2 full. But, that does make me wonder about the fuel filter again, which is now 2 yrs old.

[Roy V70 850]

Since I replaced the fuel pressure control valve connector, I've had no reoccurrence of the control valve error, I just keep getting the low pressure on the fuel rail when I put my foot down on a hill.

Yesterday, I replaced the fuel filter, which seems to have improved things so that now I really have to floor the accelerator to get the fault.

Looks like the next thing to try is the in tank fuel pump as suggested by ca2n. You do get a nice wiring sound from the pump when the ignition is turned on. I had to do this 4 or 5 times when priming the new filter. This still doesn't mean the pump is ok though.

This smacks of the same problem Reggit had in 2014.
https://www.volvoforums.org.uk/showthread.php?t=202430

I used the Icarsoft to monitor the ctrl valve current and the rail pressure and the fault occurs when the current drops to 850mA.

Hope I don't have to start replacing the high pressure pump

[ca2n]

I have yet to replace my non-operational in-tank pump and I've been running it like that for around three years.

I'm not saying that that's advisable, but from advice I've received there might not be an urgency for yours to be replaced just yet, especially as you managed to prime the fuel system upon replacing the fuel filter.

I've read your follow up thread in the Diesel Engines section and it seems a replacement HP pump didn't improve the situation.

We'll continue on that thread.

[Roy V70 850]

3 months without any problems, then the control valve error re-occurred causing fuel high pressure faults.

This is all after replacing the connector, the HP pump+regulator and having an injector replaced which was probably taken out by the high rail pressure.

I jiggled the new connector and cabling and the fault disappeared. Does anyone have any diagrams of this loom, it smacks of a connection problem. It's not shown in the Haynes manual.

[Clan]

Originally Posted by Roy V70 850

3 months without any problems, then the control valve error re-occurred causing fuel high pressure faults.

This is all after replacing the connector, the HP pump+regulator and having an injector replaced which was probably taken out by the high rail pressure.

I jiggled the new connector and cabling and the fault disappeared. Does anyone have any diagrams of this loom, it smacks of a connection problem. It's not shown in the Haynes manual.

volvo do a repair kit for the tank pump connecting wires .

[Roy V70 850]

Sorry, I didn't make myself clear. Its the wiring to the high pressure regulator valve that seems to be the problem. It appears to be going open circuit thereby demanding full pressure on the rail.

I already bought the Volvo repair kit and fitted for that. I just wonder if there is a connection problem at the other end (connector block?), but I don't have any diagrams.

[Clan]

Originally Posted by Roy V70 850

Sorry, I didn't make myself clear. Its the wiring to the high pressure regulator valve that seems to be the problem. It appears to be going open circuit thereby demanding full pressure on the rail.

I already bought the Volvo repair kit and fitted for that. I just wonder if there is a connection problem at the other end (connector block?), but I don't have any diagrams.

All the sensors go direct to the Engine ECU so no further connectors , The ECU connector is excellent quality but worth visibly checking and check the loom for rubbing anywhere on the engine or gearbox ....