Posting this as it may help others.
I bought my car last November and the stop start never realy worked that great "high power consumption" but always got great mpg.
Would get 57 to 60mpg on my 40 mile commute to work but in October it starting dropping off.
Then my auto hold would start to stick when trying to move off but only if auto start stop had kicked in.
Then my rear wiper would sometimes only wipe halfway then stop and my lock sound stopped, by this time my mpg was now down to 48mpg.
I had no fault codes but while doing a scan I noticed my battery was only at 11.9 volts.
So I took the car for a long run down to Carlisle and back to ayrshre and it only charged to 75% and noticed the alternator was constantly trying to shove 14.9 volts down the battery.
So long story short, I got a new battery, and happy to say after a month all problems have disappeared and mpg is back to a reasonable 56 winter mpg.
Auto hold works fine, start stop works fine, rear wiper works fine and the locking chirp is back.
Also the old battery was coded as efb rather than AGM battery and it was AGM battery that was in place.
Hope this comes in useful for someone
I bought my car last November and the stop start never realy worked that great "high power consumption" but always got great mpg.
Would get 57 to 60mpg on my 40 mile commute to work but in October it starting dropping off.
Then my auto hold would start to stick when trying to move off but only if auto start stop had kicked in.
Then my rear wiper would sometimes only wipe halfway then stop and my lock sound stopped, by this time my mpg was now down to 48mpg.
I had no fault codes but while doing a scan I noticed my battery was only at 11.9 volts.
So I took the car for a long run down to Carlisle and back to ayrshre and it only charged to 75% and noticed the alternator was constantly trying to shove 14.9 volts down the battery.
So long story short, I got a new battery, and happy to say after a month all problems have disappeared and mpg is back to a reasonable 56 winter mpg.
Auto hold works fine, start stop works fine, rear wiper works fine and the locking chirp is back.
Also the old battery was coded as efb rather than AGM battery and it was AGM battery that was in place.
Hope this comes in useful for someone
