Help! We have an SMAX  which had the engine malfunction sensor show + went into limp mode. It has now been to a garage 3 times in 8 weeks, during which time it has had the filter cleaned; filter replaced; temperature sensor in the exhaust replaced and again, after approx 100 miles when cruising down the motorway ( not driving like a girl but thrashing at 3000 + revs as advised!) it is still setting engine malfunction warning off. It then takes approx a week before it goes into limp mode. Does anyone have any experiences that they could share? Remember reading somewhere about the actual garage may need their Ford diagnostics updating?  Off to cornwall in July - don't want to go at less than 3000 revs. Also costing a fortune ...

15 hours ago, Katy & Trev said:

We have an SMAX  which had the engine malfunction sensor

Hi,

Could you provide a few more details about engine type etc. More likely to find someone with helpfull hints then.

I am not sure about the advice to go at 3000rpm+, unless it is a diesel with DPF, and they think it needs a regen.

The garage sound a bit dubious, have they provided a list of the DTCs (error codes) that they have read?

There is lots of info on this site about reading error codes yourself, it can do no harm, and may be Very helpful.

Post here if you want more info.

Peter.

 

Has the dpf pressure sensor been changed?

And was it a ford garage?

Going to the garage tomorrow as the engine light has come on tonight, so that means it'll go into limp mode again soon. I will ask for the dtc codes before asking them to do any more work and see if anyone can help. Many thanks. I think they changed the temperature sensor last time but assume this is different to the dpf pressure sensor. I'll ask - they're Ford approved and service lots of Ford fleet vehicles.

 

how old is your smax, and the pressure sensor is different to the temp sensor, its the pressure sensor that normally goes out of range, but wont trigger a sensor dtc, it normaaly triggers a dpf dtc thinking dpf is blocked when it isnt. your ford dealer can check it out by reading the signal voltage. too high a voltage with ign on only means sensor has "failed in range"

this may not be the issue but im guessing it could be.