Engine malfunction 'service now' warning... what could it be?

Advice Needed
1

I just bought a 2014 1.6 TDCi Ford Focus from a private seller. On my way home, everything was fine as I was accelerating normally. But once I hit a 70mph road, I decided to really push it, and that’s when things went wrong. The car went into limp mode, showed a ‘service now’ warning, and I could barely accelerate. I turned it off, restarted, and it seemed fine again. But when I pushed it hard once more, the same thing happened. Any thoughts on what’s going on?

2

It sounds like your Focus is having a common issue with going into limp mode. The fact that it happens when you accelerate hard suggests a few possibilities:

  1. Turbo Issues: The turbo might have a problem, like a worn actuator or a blocked pipe, which causes the car to go into limp mode.

  2. Boost Pressure Sensor (MAP Sensor): A bad or dirty sensor could send wrong signals to the ECU, causing it to reduce power to protect the engine. You might want to get a diagnostic scan to check it.

  3. Mass Airflow Sensor (MAF): If this sensor is dirty or not working right, it can affect how the engine performs, especially under heavy load.

  4. EGR Valve: A faulty or clogged EGR valve can mess with engine performance and activate limp mode.

  5. Fuel Delivery Problems: Issues with fuel pressure or a clogged filter could cause power issues when you accelerate hard.

  6. DPF or Exhaust Issues: If the Diesel Particulate Filter (DPF) is clogged, it could trigger limp mode, especially if there’s a faulty exhaust gas temperature sensor.

Have you tried scanning it yet? A quick check with an OBD2 scanner should tell you more.

3

@Shawn
Thanks for the ideas! I’m going to get it plugged in today, this helps a lot!

4

@Shawn
Update: It turns out the issue is with injector number 3, that’s what the code reader showed.

5

Huxley said:
@Shawn
Update: It turns out the issue is with injector number 3, that’s what the code reader showed.

I had the same thing happen last week, I was going to suggest this.

6

@Nico
Did fixing the injector solve the problem for you?

7

Huxley said:
@Nico
Did fixing the injector solve the problem for you?

Yeah, I got injector 3 replaced and it’s working fine now. I had to limp it to a garage, they diagnosed it and fixed it the same day.

8

@Nico
That’s great to hear! How much did it cost?

9

Huxley said:
@Nico
That’s great to hear! How much did it cost?

It was around £425. Since it’s a company car, my boss paid for it. You could probably get it cheaper, around £300-£400.

10

My suggestion is to pull the codes so you’re not just guessing. No one can really know what’s wrong without seeing what codes are set.