I have recently taken my 2014 1.6 tdci to a tuner, they asked me to re-connect the battery after putting the ecu back in, after mapping.

The car starts but runs very rough for a couple seconds and cuts out.

Fault codes show - Faulty fuel injector driver within the PCM

Could this be caused by connecting the battery incorrectly earth lead, i.e sparking to chassis when reconnecting it etc. If not, what could have caused it

A new ecu has been ordered.

Thanks in advance

If it ran without issue beforehand, then the fault lies with the tuner. Who is the company that mapped it for you ??

I would rather not name the tuner. I re-fitted the ecu after flashin. I just want to make sure I couldn't of done it, connecting the battery back up, which was implied. We were both under the bonnet when it was being re-fitted.

It's accepted practice that the negative cable is disconnected first & reconnected last

Exactly what was done. I'm a trained technician, however some vehicles have their traits. Especially newer. I'm not so familiar with the newer 1.6 tdci

Connecting battery wont damage the ecu, its the flashing that has. No doubt about that.

I agree with Ian above - sounds like a mistake has been made by the tuner

OK. Thanks for your replies. My mind has been put to rest

What was the dtc, was it just 1 injector driver circuit? Also when fitting ecu were any of the pins bent when refitting the plugs?

We checked the pins, all were OK. It was injector driver circuit failure, If I remember rightly. I saw it on their laptop, so didn't take note. P0200 or p1200 I think. Injector driver circuit failure on pcm.

Also Def had P068A/001674 - ECM Power Relay Load Circuit: De-Energized Performance Too Early, I assume that's just disconnecting / reconnecting the battery?