MY2016 Evoque Autobiography 2.0L DIESEL 5 DOOR / L538
Here you go KrissKross:
Hi Krisskross,Problem seems to be sorted.
It looks like it started when dealer put a new battery for a test drive (the existing one allowed only for opening door) and, obviously, did not register it to the car ECU.
As an effect there was a strange behavior of alternator leading to flat discharge that battery over the period I was struggling with warning on dashboard.
I had to buy a new battery. I was happy only for three days and the symptoms returned.
So one rainy day I opened the bonnet and started measuring volts.
Charging on idle: 14.5V
So far, so good. Soon as I shut the bonnet the warning returned (engine was on!).
I opened the bonnet again and measured volts again: 14.5 wtf?
In a desperation I put the multimeter on a windscreen to observe it for a longer time from behind the wheel.
And now the best part of the story:
When I closed the bonnet the charging gone - 11.5V. Some swears later I decided to sit in a car to cool down.
At the very moment of opening door the charging returned. I had 14.5V on a meter again! I tried that trick with boot lid and it worked the same way
How about driving it?
No charging at all. Continuous, slow Volt drop. Until deceleration. Believe me or not, but it started charging when I took foot away from pedal letting it roll down from a hill. 14.5-16V depending on revs.
Having in mind that driving car with opened door or boot is not quite legal I tried the last trick with resetting ECU by shorting cables going normally to the battery (for about 3 minutes for total discharge any internal capacities). That restored the charging on idle also sorted the problem with the door or bonnet to be open but did not solve the problem with warning.
Because my local garage became operational after that crazy covid time I took the car there for diagnostics.
All they done was flushing ECU errors and registered battery. 15 minutes of clean job. Story of abnormal charging behavior didn't impress the technician as he faced it before. He said he's actually got more interesting case of LR on a shopfloor with wipers working only when indicator lever is on 'left' position.
Day with no warning: 3rd.
😲. Lesson learned there then Maffy.Modern Cars are a big issue, Mrs M's Golf R had stood still for a few weeks, decided it needed a run--click, click click-Flat battery, jumped started and blew the Infotainment system and I mean fried-at the dealer now being sorted and replaced NOT a cheap day out that's for sure-looking at £1,400 or so.
Expensive flat battery!!!!!!!