My company has a Chevrolet Captiva LT 2009 model. Since April 2011 the vehicle was emitting thick black smoke and engine warning lights were glowing.
The vehicle was sent for servicing several times and finally the injector was replaced with a new one.
Two days back again we had engine warning light glowing and AC was not functioning properly. But this time we did not have emission problem. Now the mechanic says that ECM (Electronic Controller Module) has problem and needs replacement.
How this ECM fails suddenly?
Is there any chance of ECM fails due to mishandling when engine is removed several times while attending excessive smoke complaint?
It sounds like this repair shop might be just replacing parts until they find the problem. I would take the vehicle to a shop that actually knows how to diagnose a problem.
If you want to let them replace it you can, but just get an agreement in writing that if that does not fix the problem then you don't have to pay for it.