Engine light

BanjoSpanner

I have a 2012 2.0 diesel Mondeo.

The engine light is on with code P00BD.

I know the code relates to air flow and so forth. But the strange thing is this..... if I switch off the engine light using a handheld code reader, and set out on my regular commute the following morning, the engine light comes back on at exactly the same point in my journey every day, I mean exactly the same point. It has gotten to the stage now where I know it is coming, and my eyes are watching the dash and sure enough, on comes the light exactly when expected. And always with P00BD.

Anyone seen anything like that before?

bazz26

All you are doing with the handheld code reader is clearing the fault code. Clearing the fault code/engine warning light doesn't fix the problem causing the fault code. The underlying problem is still there and all that is happening is when the ECU runs a routine diagnostic on the car's systems it just flags the same fault again and switches the engine management light on. If you want the fault to go way permanently then you need to get the underlying problem fixed.

larchielads

It wont go away permanently til its fixed, think the code is for MAF sensor. Had similar code on her qashqai for maf sensor, turns out it wasnt the sensor itself but the air intake pipe was broken replaced it with part from amazon 2euro and my socket set. 5 min job.

Now yours might not be the sensor itself but a reason as to why the sensor is not working properly. As in my case the air intake pipe was broke and i do mean broke. In 2 halves, litteraly, must be a weak spot in the pipe. Check for holes in rubber pipes in and around the sensor, the intake pipe, check the actual sensor. Hopefully its a cheap and easy fix. If all comes to all bring to a trusted local garage.

kirving

The car won't give an error immediately - as it's difficult for the computer to detect an anomaly while everything is heating up and reaching a steady state.

The reason the light is coming on at the same time each day is that there is either a "time since engine start", or "distance travelled since engine start" clock running on the computer, before which the light will not come one.

I did have an issue on a previous car, whereby in one car park I go to in the Wicklow mountains, the automatic gearbox would sometimes not allow me to select reverse. Never ever happened anywhere else. I can only imagine it was a shallow underground cable causing interference or something, never got to the bottom of it.

BanjoSpanner

Thanks for all the replies. I knew it must have been something to do with maybe distance travelled or perhaps engine temperature before the light would come on. I had thought that engine temperature was unlikely because it would be incredible if the engine reached the exact same temperature at the exact same stage of the journey every day. So the distance travelled idea seems far more plausible.

I'm sure it's an air leak somewhere. Now to go tracing pipes looking for it, might have to make my own smoke machine if I don't see any obvious holes or cracks.

Thanks again!