engine malfunction

[Mike 59]

My mondeo 2009 2.2 deisel, engine malfunction light comes on when driving down hill. what will cause this?

[nicam49]

I didn't like driving down that steep hill in Porth! Can't imagine what it's like in winter.... 🤔          Welcome to the forum, by the way. 😀

[TomsFocus]

1 minute ago, nicam49 said:

I didn't like driving down that steep hill in Porth! Can't imagine what it's like in winter.... 🤔 

You just have to take it Caerphilly...  

 

1 hour ago, Mike 59 said:

My mondeo 2009 2.2 deisel, engine malfunction light comes on when driving down hill. what will cause this?

Are you coasting/engine braking at the time?  Brakes applied for an extended period?  

Ideally you'd need to get the fault codes read though.

[Mike 59]

sometimes coasting if the hill is not steep. But not extended braking. But the malfunction light always comes on.

[TomsFocus]

Hmm, nothing obvious comes to mind unfortunately.  If you can get the codes read that'll give us a better idea.  Ideally with Forscan but even a basic OBD reader may work.

[Mike 59]

Hi Tom,

No codes showing on a borrowed OBD scanner...prob have to go to ford?

 

cheers for your reply though.

[nicam49]

Would be cheaper to buy your own dedicated Ford reader as a lot of bog standard readers don't get the Ford codes. I can recommend those suppied by Tunnelrat Electronics, around £20 so not expensive and a good investment if you intend to keep the car. 

[aptsys]

Check the O2 sensor readings whilst driving downhill. It's a common symptom of a failing O2 sensor on these diesel engines