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

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. 😀

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.

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

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.

Hi Tom,

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

 

cheers for your reply though.

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. 

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