Skip to content
View in the app

A better way to browse. Learn more.
Ford Owners Club - Ford Forums

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.



Join the Independent Ford Owners' Club

Our community has been built by enthusiasts, for enthusiasts, and proudly run by Ford owners' for over 18 years. As an independent, non-official club, everything you’ll find here, advice, support, and opinions, comes directly from members with genuine Ford ownership experience.

Join our friendly community... it's Free!

 

2010 1.6 TDCi Underboost - super low VGTDC value (~5%)

sushilovin
sushilovin
in Ford Focus Club

Featured Replies

Hi folks,

First post here. I bought a 2010 Focus 1.6 TDCi (108) around mid August, knowing it had some issues. EML is lit and my diagnostic plug in gives two codes: P042F EGR stuck closed and P0299 Turbocharger Underboost.

I have been monitoring both issues separately while driving to try to diagnose the faults as I don't believe they are related and EGR is easy enough to sort out.

I noticed a few days ago that my OBDII app detects a sensor for VGT Duty Cycle. I started tracking this and noticed that (once the warm-up cycle is complete and the EGR duty reads zero) the VGTDC sits at around 4.8% all the time. Yes, FOUR percent.This is regardless of whether I am at idle or WOT. I understand this means the turbo is basically fully open all the time?

Restarting the engine causes it to jump back up to around 70% at idle, which it pretty much normal from what I hear, with normal WOT reading around 40% (haven't tested my own "normal" WOT as EGR opens again too). I have suspected the turbo solenoid (or Turbo Boost Regulator Valve, as Ford calls it IIRC) for a while but haven't had it replaced yet. 

What would cause the VGTDC to sit so low constantly? Should I just go right ahead and replace the solenoid or try other things first? Any insight would be massively useful and appreciated. I can attach data if needed, I have collected a lot over the past few weeks. Thanks!

TL;DR: VGTDC sits at 4.8% at idle and WOT. Correct values should be around 70% at idle and 40% at WOT, from my research. Why?

  • Quote


    • Latest Deals

    Ford UK Shop for genuine Ford parts & accessories

    Disclaimer: As the club is an eBay Partner, The club may be compensated if you make a purchase via the club

    Join the conversation

    You can post now and register later. If you have an account, sign in now to post with your account.
    Note: Your post will require moderator approval before it will be visible.

    Guest
    Reply to this topic...
    Go to topic listing

    The "Digestive"

    • The Digestive Forum Roundup (31st May - 7th June 2026)

      Steve ·
      The Digestive Forum Roundup (31st May - 7th June 2026) We hope you’re all enjoying your week and finding time for some time enjoying your Ford! This week, our vibrant forum has been buzzing with discussions that touch on a diverse range of Ford models, from the Mondeo to the Fiesta and Focus. Here’s a recap of some key conversations that might pique your interest. Starting with the Mondeo, user Frenchspanner shared a particularly frustrating issue relating to a 'Immobiliser Active' message appea
      Steve
      Steve
      • 95 views





    Background Picker
    Customize Layout

    Account

    Navigation

    Search

    Search

    Configure browser push notifications
    Chrome (Android)
    1. Tap the lock icon next to the address bar.
    2. Tap Permissions → Notifications.
    3. Adjust your preference.
    Chrome (Desktop)
    1. Click the padlock icon in the address bar.
    2. Select Site settings.
    3. Find Notifications and adjust your preference.