Hi I have just had my ECU replaced , I took the car in to be mapped due to ongoing issues. the mechanic said he could do it for me and said he could also improve the performance etc . After a few days he told me there was a issue and he had shorted the ecu  and had to get it repaired. In the end after 6 weeks with no car because of postal strikes Xmas etc i got my car back initially  all seem good plenty of power smother than before  , however i have noted my MPG is significantly less gown by about 10 mpg  and the cruise control no longer works , I am a bit reluctant to let him at it again has anyone got any ideas could it just be a bit of adjustment to the programme or is it a major issue if it is a prog issue will for scan sort it or detect it a normal code reader has npt deytwcted any issues or codes ..thanks  

Personally I'd get a secondhand working ECU of the same part number as yours. Then I'd fit it to the car and use FORScan to download and install the 'AsBuilt' file for your car.

Once everything is back to standard you can fault find from there, and if you should feel the urge to get the replacement 'mapped' then take the car to a proper automotive tuning garage.

Why did he need to remove or mess with the PCM (ECU) to remap your car?

1.6 TDCi remaps through the OBD port?

If you've had a replacement PCM fitted then it probably hasn't been re-configured to your car properly.

Warning though, any further adjustments may loose your remap software and default the car back to standard

no one seems to explain it...

when adding cruise to her indoors' car one has to fix / remember to include so you don't land with an empty vid block issue... as you write the data back you can end up with bits missing in PCM ...it needs the extra tick box / info on how cruise controls the fly by wire throttle

my understanding no one disputed (but happy to hear the real way it works) is there are / can be three bits of logic inside the PCM 

the map it runs on
the immobiliser garbage
a populated vid block that knows how to make the cruise control work

I guess on your car now, the ECU he's given you is from a non cruise car and he couldn't retrieve yours to include on the replacement map - so one could get this one fixed by a guru that adds the info back in to make cruise work, and or you start again with the asbuilt map (and lose the tune up)

if its a turbo tractor and you make use of extra go - it will never be free

 

 

13 hours ago, Botus said:

I guess on your car now, the ECU he's given you is from a non cruise car and he couldn't retrieve yours to include on the replacement map - so one could get this one fixed by a guru that adds the info back in to make cruise work, and or you start again with the asbuilt map (and lose the tune up)

Yes, as I explained it

 

On 1/19/2023 at 7:56 AM, DaveT70 said:

If you've had a replacement PCM fitted then it probably hasn't been re-configured to your car properly.

The donor PCM was non cruise and not reconfigured to your car's spec BEFORE the remap software was added.

To add cruise now you will (probably) loose the remap

great, but you don't tell him exactly what is missing, you just add a scare story about losing the tune up - which is easier to keep than adding the logic to make the cruise function again

 

I wasn't contradicting or dissing your post - I was trying to explain how the logic inside the ECU works and what went wrong during the swap

Hi all,the car went in to have a egr delete and map he contacted my after a couple off days and said he couldn't get access via the odb port so he had to do it on the bench he told me that he accidently shorter it out and had to send it for repair..he then said it still didn't work and said he had to get another one to cut a long story short he was a total cowboy even smashed the ecu bracket ...myself I do not understand pcms odbs ecus programs or modules I am a spanner man ....all I know is the ecu he has fitted is different to the number ford supplied from the reg.. Strange that I can find dozens of ecus for a 1.6 tdci but non with my with my part no  surely min isn't that unique