UK Auto Repair Questions?
Hopefully i can help..
What engine does the car have exactly?
Has this been an ongoing problem and has anything been inspected or replaced so far?
Ok..the issue you have as per serv light/loss of power is down to the ECU detecting a fault on the engine.in your case an intermittent one.this in turn can cause the car to go in home mode/reduced power - because its acting out intermittent its going to make disgnoses a little harder..usually when that occurrs it has to be diagnostically tested - the car plugged in and see what fault code its logging in the fault memory.then take steps to make checks based on that code..it might still be possible to that even though the warnings out "i asume" to see if any codes are still present..some of the most common faults you normally see on these cars diesel i mean are Turbo boost faults,intercooler pipe tears,vacuum pipe issues,sticking EGR valves "can be cleaned",DPF issues.blocking up normally on cars seldom used or DPF pressure pipes breaking,..however as it stands as and when that fault occurrs it will need diagnostically tested..sometimes a garage might not find anything if the car at the moment seems to run ok..in that case "if" possible you may want to leave the car with the garage you use,provided they have the proper diagnostic equipment to test the car a few days for them to actually catch the fault as and when it happens so to speak...I do hope this helps..If you require to ask anything further then please do so before you rate