P0299 Turbo underboost error

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Robk
(Donor 2023)
Posts: 12
Joined: 30 Jul 2023, 13:19
x 1

P0299 Turbo underboost error

Unread post by Robk »

I have a P0299 error code and the car is not going into boost.
I have done some research and the it seems that the suspect areas are as below.
Any ideas where I should start looking?
VIN VF7**************[VIN obfuscated, can be read by forum staff]

Suspect Areas:
Turbocharger pressure regulation electrovalve
Turbocharger discharge electrovalve
Inlet manifold
Vacuum pump
Vacuum duct for the diaphragm of the turbo pressure regulation electrovalve
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GiveMeABreak
(Donor 2016)
Posts: 42019
Joined: 15 Sep 2015, 19:38
x 6955

Re: P0299 Turbo underboost error

Unread post by GiveMeABreak »

Fault Code: P0299
Description of Fault: Turbocharging circuit: Pressure too low. Turbo pressure too low: Turbo regulation at the minimum limit.

Description of the diagnostics:
The difference between the reference turbo pressure and the actual pressure falls below the threshold of -0,1 bars or -0,12 bars if there is an error in the camshaft dephasing system. No confirmation time
Conditions of activation of the diagnostics The following conditions have to be met
- Engine management ECU in main triggering phase
- Turbo regulation active
- Atmospheric pressure higher than 0,8 bars
- Engine speed above a threshold dependent on atmospheric pressure
- Turbo pressure valid
- No power step error
Conditions for Fault to clear: The following conditions have to be met:
- Must be within 8 s after the appearance of the fault (Deactivation of the turbo regulation 8 s after the appearance of the fault)
- After engine restart (If the difference between the reference turbo pressure and the actual pressure exceeds the threshold of - 0,1 bars or - 0,12 bars if there is an error in the camshaft dephasing system)
Downgrade Modes whilst Fault is active:
  • Deactivation of the turbocharger regulation (Electrovalve forced wide open)
  • No authorisation of checking of the power stage of the dump valve
  • Reduction of load applied to revert to the behaviour of a naturally-aspirated engine (The maximum load is limited by the mapping : 110 % to 2000 rpm ; 40 % to 6500 rpm)
  • Switching on of the warning lamp and/or warning message: "SERVICE" warning lamp possible, MIL warning lamp possible
Symptoms:
  • Lack of power
Suspect Areas:
  • Turbocharger pressure regulation electrovalve
  • Turbocharger discharge electrovalve
  • Vacuum pump
  • Air cleaner
  • Air inlet line
  • Turbocharger boost sensor
  • Vacuum circuit
  • Turbocharger pressure regulation capsule
Please note, I'm no longer active on the Forum, so won't respond to messages.

Marc
Robk
(Donor 2023)
Posts: 12
Joined: 30 Jul 2023, 13:19
x 1

Re: P0299 Turbo underboost error

Unread post by Robk »

Thanks for the help. It was a simple fix. The small plastic part that connects to the turbo inlet from the air intake was misaligned. Tightened it and error is gone.
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GiveMeABreak
(Donor 2016)
Posts: 42019
Joined: 15 Sep 2015, 19:38
x 6955

Re: P0299 Turbo underboost error

Unread post by GiveMeABreak »

There you go, not always expensive or complicated! :wink:
Please note, I'm no longer active on the Forum, so won't respond to messages.

Marc