Depollution Fault 1.6 HDI GP

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Delvey
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Re: Depollution Fault 1.6 HDI GP

Post by Delvey »

I'm hopefully going to strip the turbo at weekend and check all the hoses. Have been reading around and seen people using Mr Muscle to clean the vanes. The exhaust side of the turbo seems easy to get to so would it be worth giving it a go?
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Re: Depollution Fault 1.6 HDI GP

Post by MikeT »

You've checked the actuator arm moves on engine startup (you can also push it down manually with your hand) so I'd assume the vanes are moving ok.
It's the turbo copy position sensor that's under suspicion now so I'd check the live data under driving conditions to see if it changes from 100%
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Re: Depollution Fault 1.6 HDI GP

Post by Delvey »

MikeT wrote: 30 Jul 2018, 11:24 You've checked the actuator arm moves on engine startup (you can also push it down manually with your hand) so I'd assume the vanes are moving ok.
It's the turbo copy position sensor that's under suspicion now so I'd check the live data under driving conditions to see if it changes from 100%

Still stuck at 100%. Had to swap the radiator fan out. Had a quick look for the position sensor but I cannot see it at the turbo. Is it mounted at the top of the engine near the EGR or elsewhere? And a part number for the DV6TED4?
Thanks
EDIT: by the looks of it, it is underneath the actuator, hence why I could not see it
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Re: Depollution Fault 1.6 HDI GP

Post by RichardW »

That's the wrong turbo - looks like the 2.0 to me. There is no sensor on the 1.6 Turbo - only on the vac solenoid, which is buried down the back of the block, towards the RHS side of the car.
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Re: Depollution Fault 1.6 HDI GP

Post by Delvey »

RichardW wrote: 31 Jul 2018, 06:20 That's the wrong turbo - looks like the 2.0 to me. There is no sensor on the 1.6 Turbo - only on the vac solenoid, which is buried down the back of the block, towards the RHS side of the car.

Thanks. Thought so.
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Re: Depollution Fault 1.6 HDI GP

Post by Delvey »

So been having a look today. Turbo has no play in the cartridge and is spinning freely. The turbo seal on the previous page is ruined and split in half so a new one is on the way. I've also got a new air filter just to make sure
As for the solenoid on the rear. Pain in the ass to get to. Going to borrow some ramps next weekend to try and get it off. Anyone know if this engine has the solenoid with the spongy filter
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Re: Depollution Fault 1.6 HDI GP

Post by Delvey »

New turbo solenoid valve installed today. Still stuck on 100%
I also checked the tubes attached to it where I could and they seem to be in good condition. The only other thing to check in regards to the solenoid valve is the electric supply. To check this do I just attach a volt meter to the two connectors inside once it is off the valve?
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Re: Depollution Fault 1.6 HDI GP

Post by MikeT »

To be honest, this turbo copy position sensor eludes me. I've never been able to figure out what it looks like or where it's located.
The logical assumption is it's incorporated into the regulator valve that you've just replaced, but how does it work if there's just two wires?
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Re: Depollution Fault 1.6 HDI GP

Post by Delvey »

MikeT wrote: 18 Aug 2018, 16:09 To be honest, this turbo copy position sensor eludes me. I've never been able to figure out what it looks like or where it's located.
The logical assumption is it's incorporated into the regulator valve that you've just replaced, but how does it work if there's just two wires?

it is two wires and 3 vacuum lines.
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Re: Depollution Fault 1.6 HDI GP

Post by xantia_v6 »

It is a simple electric solenoid working against a spring, so the movement is proportional to the current applied. The ECU supplies a variable current to control it.

The trick is that the system continuously calibrates itself by monitoring the level of turbo boost relative to the current applied and other engine conditions.
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Re: Depollution Fault 1.6 HDI GP

Post by MikeT »

I mean, assuming the two wires power the solenoid, how does it "sense" and report the position in order to determine "copy position" that's displayed in Lexia?
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Re: Depollution Fault 1.6 HDI GP

Post by xantia_v6 »

The copy position is measured by the pressure sensor after the turbo.
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Re: Depollution Fault 1.6 HDI GP

Post by MikeT »

xantia_v6 wrote: 18 Aug 2018, 16:59 The copy position is measured by the pressure sensor after the turbo.
So the MAP provides both data for intake pressure and (the ECU) infers the turbo regulator solenoid valve position from it (and poss other data) as well?
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Re: Depollution Fault 1.6 HDI GP

Post by GiveMeABreak »

Just going back to what you were saying earlier about not problem at high speed driving, but the issue is with idling / low speed in relation to the turbo:

The turbine, activated by the exhaust gas, drives the compressor which compresses the inlet air.
The rotation of the fins on their respective shafts permits:
  • Variation of the inlet section of the exhaust gases onto the exhaust turbine
  • More precise direction of the exhaust gases onto the exhaust turbine
Regulation of the boost pressure is progressive and is controlled by mapping (engine ECU).

Note: When the turbo pressure regulation electrovalve is not supplied, the mobile fins are in the open position.

Operation at Low Speed
C4GP Turbo A.PNG
At low engine speed the kinetic energy of the exhaust gases is weak . The variable geometry turbocharger increases the kinetic energy of the exhaust gases by decreasing the section through which the exhaust gases must pass.

Furthermore the mobile fins ( 18) in the closed position precisely direct the exhaust gases onto the exhaust turbine (20).

With these two conditions the rotation speed of the exhaust turbine is accelerated at low engine speed.
Operation at High Speed
C4GP Turbo B.PNG
At high engine speed the kinetic energy of the exhaust gases is strong . The variable geometry turbocharger decreases the kinetic energy of the exhaust gases by increasing the section through which the exhaust gases can pass.

Furthermore the mobile fins ( 18) in the open position direct the exhaust gases onto the exhaust turbine (20) in a less direct manner.

With these two conditions the rotation speed of the exhaust turbine is reduced at high engine speed.
Here's the Turbocharging pressure regulation solenoid valve:
Role
The regulating electrovalve controls the boost pressure waste gate.
Role of the boost pressure regulating electrovalve:
  • Regulate the boost pressure
  • To limit the boost pressure
Regulation of the boost pressure is progressive and is controlled by mapping (injection ECU).
C4GP Turbo C.PNG
(30) Electrical connector.
  • k: Pressure drop inlet for the vacuum pump.
  • l: "user" outlet.
  • m: White marking.
N.B. : The white marking indicates the outlet aperture for the turbocharger regulation control.
The solenoid control is an OCR (Opening Cyclical Ratio) type control.
The proportional electrovalve controlled by an OCR voltage is connected to the following components:
  • Atmospheric pressure
  • Vacuum supplied by the vacuum pump
The pressure supplied by the electrovalve is included between the atmospheric pressure and the vacuum pump vacuum.

Electrical special features
Features of the OCR signal:
  • Supply voltage: 12.5 Volts
  • Frequency: 140 Hz
  • Fixed period: 7 ms
  • Resistance at 20 °C : 15.5 ± 0.7 ohms
  • Maximum vacuum: 800 mbars
Open Cycle Ratio (OCR)
C4GP Turbo D.PNG
  • E: Depression in m.bar.
  • F: Open cycle ratio (OCR) (in %).
  • G: Time (ms).
  • V: Voltage In volts.
  • T: Fixed period 7 ms or 140 Hz.
  • Ton: Variable time.
The open cycle ratio (OCR) is determined by the ratio of the variable time ( Ton) to the fixed period (T).
% OCR = (Ton/T) x 100.

The mean voltage (Tm) supplies the turbo pressure regulation electrovalve.
  • The greater the OCR percentage, the higher the mean voltage (T1).
  • The smaller the OCR percentage, the lower the mean voltage (T2).
Variable voltage control (OCR):
  • Full supply (maximum OCR) = Maximum vacuum (800 mbars)
  • No supply (minimum OCR) = No vacuum (atmospheric pressure)
So this is how the system works on your C4GP with the Bosch Injection. So maybe you can look at this info compared to what Diagbox is telling you about the % and what it should be. Maybe they vacuum is supply is faulty then?
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Re: Depollution Fault 1.6 HDI GP

Post by Delvey »

MikeT wrote: 18 Aug 2018, 17:05
xantia_v6 wrote: 18 Aug 2018, 16:59 The copy position is measured by the pressure sensor after the turbo.
So the MAP provides both data for intake pressure and (the ECU) infers the turbo regulator solenoid valve position from it (and poss other data) as well?

Maybe the MAP is faulty then
GiveMeABreak wrote: 18 Aug 2018, 18:00 Just going back to what you were saying earlier about not problem at high speed driving, but the issue is with idling / low speed in relation to the turbo:

The turbine, activated by the exhaust gas, drives the compressor which compresses the inlet air.
The rotation of the fins on their respective shafts permits:
  • Variation of the inlet section of the exhaust gases onto the exhaust turbine
  • More precise direction of the exhaust gases onto the exhaust turbine
Regulation of the boost pressure is progressive and is controlled by mapping (engine ECU).

Note: When the turbo pressure regulation electrovalve is not supplied, the mobile fins are in the open position.

Operation at Low Speed
C4GP Turbo A.PNG
At low engine speed the kinetic energy of the exhaust gases is weak . The variable geometry turbocharger increases the kinetic energy of the exhaust gases by decreasing the section through which the exhaust gases must pass.

Furthermore the mobile fins ( 18) in the closed position precisely direct the exhaust gases onto the exhaust turbine (20).

With these two conditions the rotation speed of the exhaust turbine is accelerated at low engine speed.
Operation at High Speed
C4GP Turbo B.PNG
At high engine speed the kinetic energy of the exhaust gases is strong . The variable geometry turbocharger decreases the kinetic energy of the exhaust gases by increasing the section through which the exhaust gases can pass.

Furthermore the mobile fins ( 18) in the open position direct the exhaust gases onto the exhaust turbine (20) in a less direct manner.

With these two conditions the rotation speed of the exhaust turbine is reduced at high engine speed.
Here's the Turbocharging pressure regulation solenoid valve:
Role
The regulating electrovalve controls the boost pressure waste gate.
Role of the boost pressure regulating electrovalve:
  • Regulate the boost pressure
  • To limit the boost pressure
Regulation of the boost pressure is progressive and is controlled by mapping (injection ECU).
C4GP Turbo C.PNG
(30) Electrical connector.
  • k: Pressure drop inlet for the vacuum pump.
  • l: "user" outlet.
  • m: White marking.
N.B. : The white marking indicates the outlet aperture for the turbocharger regulation control.
The solenoid control is an OCR (Opening Cyclical Ratio) type control.
The proportional electrovalve controlled by an OCR voltage is connected to the following components:
  • Atmospheric pressure
  • Vacuum supplied by the vacuum pump
The pressure supplied by the electrovalve is included between the atmospheric pressure and the vacuum pump vacuum.

Electrical special features
Features of the OCR signal:
  • Supply voltage: 12.5 Volts
  • Frequency: 140 Hz
  • Fixed period: 7 ms
  • Resistance at 20 °C : 15.5 ± 0.7 ohms
  • Maximum vacuum: 800 mbars
Open Cycle Ratio (OCR)
C4GP Turbo D.PNG
  • E: Depression in m.bar.
  • F: Open cycle ratio (OCR) (in %).
  • G: Time (ms).
  • V: Voltage In volts.
  • T: Fixed period 7 ms or 140 Hz.
  • Ton: Variable time.
The open cycle ratio (OCR) is determined by the ratio of the variable time ( Ton) to the fixed period (T).
% OCR = (Ton/T) x 100.

The mean voltage (Tm) supplies the turbo pressure regulation electrovalve.
  • The greater the OCR percentage, the higher the mean voltage (T1).
  • The smaller the OCR percentage, the lower the mean voltage (T2).
Variable voltage control (OCR):
  • Full supply (maximum OCR) = Maximum vacuum (800 mbars)
  • No supply (minimum OCR) = No vacuum (atmospheric pressure)
So this is how the system works on your C4GP with the Bosch Injection. So maybe you can look at this info compared to what Diagbox is telling you about the % and what it should be. Maybe they vacuum is supply is faulty then?
So potentially the fault lies within the vacuum lines? Which are a nightmare to get to by the looks of things.
As for the low speed/high speed, the car is fine at low speed, and even at higher speeds. It seems the car only goes into limp mode when I drive above 70mph for continued periods, or up steep hills, which makes sense as earlier it seems the car will only go into limp mode once it reaches a certain amount of torque.
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