307 2.0 110bhp Turbo pressure too low / Turbo electro valve

[dackjaniels]

Hi,

307 2.0 HDI 110, EDC15C2, VIN 82375805. 5.7 Bosch ESP ECU.

Backstory: Bought car and found several errors including anti-pollution fault and ESP/ASR not functioning.
Fixed two speed sensors which cleared the coherence and open circuit errors I was having. ESP/ASR fault no longer shows when car is started

Engine light and limp mode kicks in at about 65mph in 4th or 5th gear. Not every time I reach that speed, it usually occurs uphill (slight incline on carriageway). It seems when the engine is under load at speed it's more likely to occur.

Each time it happens I get this fault:
ABS/ESP: Intermittent. Communication with the engine management ECU fault. Incorrect value received.
For many hours I was checking wiring and plugs etc thinking there may be a bad connection between the engine ECU and the ESP ECU and this was causing the limp mode.

Since then I have removed the DPF/CAT. I gutted the one-piece DPF/CAT, flashed ECU and configured with PP (removed additive ECU etc.).
Anti-pollution fault no longer appears when car is started

What I have now noticed is I still get the limp mode kicking in as per above conditions and when it does the anti-pollution and ESP/ASR not functioning faults display on the dash/MFD.
Before DPF-removal the anti-pol fault was there from start-up so the only 'new' fault to show when limp mode kicked in was the ESP/ASR fault. Now that there are no faults on start-up I can see that both the anti-pol and ESP faults are displayed when limp mode kicks in.

This was misleading to me as it convinced me the limp mode was being caused by the ESP fault. On closer inspection it seems I have a turbo pressure measured too low (anti-pol) fault which is causing the limp mode. I assume the ESP fault is a by-product of this because ESP is not supposed to function when in limp mode. Does this make sense?

This shows how an inexperienced PP user can waste a lot of time troubleshooting problems that are probably not there!

Anyway, the fault I have now regarding turbo is:

Intermittent fault. Turbo pressure. Turbo pressure measured too low.

I have attached 4 screenshots of turbo measurements taken at various rpm, these were taken whilst driving, not idling.

What is the likely cause of this?
The electro valve? How can I test this?
Split pipes? Which pipes should I check. The turbo is very inaccessible on the 110 so I'm not sure where to start.
The turbo seems fairly loud to me I wonder if there is a split somewhere. In fact it almost sounds harsh like its not lubricated correctly but I have no reference to compare it to.

I would appreciate your comments on the measures I've taken, particularly the turbo pressure vs ref values and the turbo electro valve values.

I've also attached a pic of the measures from the EGR valve/throttle electro valves. Do the values look normal for these?

Thanks,
Steve

[davidireland]

Change turbo control solenoid.

[dackjaniels]

Thank you David. Is there a way of testing the unit or can you simply tell from the stats that it isn't doing its job and definitely needs changing?

Could I swap it with another of the four electro valves, say the EGR valve one, and see if it makes a difference before I go out and buy one?

Thanks again!

[davidireland]

Originally Posted by dackjaniels

Thank you David. Is there a way of testing the unit or can you simply tell from the stats that it isn't doing its job and definitely needs changing?

Could I swap it with another of the four electro valves, say the EGR valve one, and see if it makes a difference before I go out and buy one?

Thanks again!

You can swop it, they are all the same.

[Ajek37]

I have been experiencing similar problems as you. Have you checked your ecu readings on planet? I have discovered my fuel rail pressure sensor is sjowing a permanent fault. This could be the root of my problem- as a drop in pressure could affect my vacuum. I had my turbo checked on planet and every reading was where it should be.

[dackjaniels]

Thanks David.

Originally Posted by Ajek37

I have been experiencing similar problems as you. Have you checked your ecu readings on planet? I have discovered my fuel rail pressure sensor is sjowing a permanent fault. This could be the root of my problem- as a drop in pressure could affect my vacuum. I had my turbo checked on planet and every reading was where it should be.

I've not had time to check the valve yet but don't have any other relevant faults showing up in PP so hoping it's just the valve.