Car: 2016 Ford Fiesta 1.0L EcoBoost Zetec S Red Edition 140PS, 57,000 miles, manual, 1 owner (me).

Error Code: P0234-22-66

I am experiencing an issue with my car and I am looking for advice on whether anyone would know?

Last Sunday 9th July, I was driving on an expressway slip road to go up to 70mph and after I went past 50mph, my car's engine light came on (spanner, powertrain light) and the middle infotainment screen said 'Service Car Now' or something and there was a massive loss in acceleration (the car was increasing in speed insanely slow around 50mph when my foot was pressing the accelerator all the way to the floor). I took it to People's Ford and the outcome was that there were no issues with it, they checked the error codes, they followed the procedures, my invoice says:

'Smoke test, no leaks, run sbd session, followed turbo test application all okay, actuators operating, no mechanical damage, cleared all DTCS, carried out thorough drive cycle and no fault on road test'.

People's Ford charged me £160.00 to tell me that there is nothing wrong with my car, they said it could have been an 'engine glitch' as engines sometimes experience that...? Well today, I was again driving on an expressway slip road going up to 70mph and at 50mph, the car went into limp mode again and the engine light came back on. It sounded like the car disconnected the turbo because I could no longer hear the turbo working like I normally would and the acceleration was again, insanely slow.

When you turn the car off, the car basically resets itself and my turbo starts working again, and there's no engine lights appearing on my driver dashboard.

Does anyone know what could be happening here, why is my car turning my turbo off and what can I do to fix it? Is my turbo coming to the end of its life at almost 60,000 miles?

Is this sort of problem worth fixing or should I just sell it and buy another car?

In need of some urgent help

That error code is for overboost.

It means the turbo wastegate isn't opening when it should, or as far as it should.  At that point the ECU triggers limp mode to prevent any further engine or turbo damage.

The turbo itself is likely to be fine.  More likely be the actuator at fault.  Check vacuum pump, pipework and actuator.

5 hours ago, TomsFocus said:

That error code is for overboost.

It means the turbo wastegate isn't opening when it should, or as far as it should.  At that point the ECU triggers limp mode to prevent any further engine or turbo damage.

The turbo itself is likely to be fine.  More likely be the actuator at fault.  Check vacuum pump, pipework and actuator.

Thanks for your reply.

I'm not very mechanical so I wouldn't trust myself to look at my own car. What do I need to tell Fords when I take it to them so they actually fix it this time and don't fob me off?

12 hours ago, DanielCron said:

What do I need to tell Fords when I take it to them so they actually fix it this time and don't fob me off?

Seems to be hit & miss whether you get a decent Ford tech at dealerships unfortunately.  Many won't take any notice of what you've been told on forums either.  They seem to take it as a personal attack on their work.  

In this case, I'd probably suggest taking it to an independent garage if you know of any near you that are trustworthy?  This isn't actually Ford specific, the turbo actuator system is very similar across a lot of different modern cars.

Just need to tell them that you're getting a recurring overboost fault that triggers limp mode.  If you want to suggest what they should check - vacuum pump, vacuum pipework, turbo actuator and boost solenoid.  Though as above, they might start to take offense if you list specific areas for them to check, so use your own judgement on that one.

Why do Ford just clear the DTCs first????

Read them and investigate the codes first, that's what they've charged you to do

On 7/16/2023 at 4:13 PM, DanielCron said:

Car: 2016 Ford Fiesta 1.0L EcoBoost Zetec S Red Edition 140PS, 57,000 miles, manual, 1 owner (me).

Error Code: P0234-22-66

I am experiencing an issue with my car and I am looking for advice on whether anyone would know?

Last Sunday 9th July, I was driving on an expressway slip road to go up to 70mph and after I went past 50mph, my car's engine light came on (spanner, powertrain light) and the middle infotainment screen said 'service Car Now' or something and there was a massive loss in acceleration (the car was increasing in speed insanely slow around 50mph when my foot was pressing the accelerator all the way to the floor). I took it to People's Ford and the outcome was that there were no issues with it, they checked the error codes, they followed the procedures, my invoice says:

'Smoke test, no leaks, run sbd session, followed turbo test application all okay, actuators operating, no mechanical damage, cleared all DTCS, carried out thorough drive cycle and no fault on road test'.

People's Ford charged me £160.00 to tell me that there is nothing wrong with my car, they said it could have been an 'engine glitch' as engines sometimes experience that...? Well today, I was again driving on an expressway slip road going up to 70mph and at 50mph, the car went into limp mode again and the engine light came back on. It sounded like the car disconnected the turbo because I could no longer hear the turbo working like I normally would and the acceleration was again, insanely slow.

When you turn the car off, the car basically resets itself and my turbo starts working again, and there's no engine lights appearing on my driver dashboard.

Does anyone know what could be happening here, why is my car turning my turbo off and what can I do to fix it? Is my turbo coming to the end of its life at almost 60,000 miles?

Is this sort of problem worth fixing or should I just sell it and buy another car?

In need of some urgent help

You are not the only person having this issue, lots of other people are having this issue and mine does exactly exactly the same. There is a bad flaw in that particular engine and Ford will never admit it unless it's a health and safety risk because it would cost them billions. I took it to the garage because the engine light kept coming on and they told me that it wasn't just me and this was a general issue that a lot of people are having.