Hello,

I was driving home today and the RPM gauge went to 0 for a few seconds then came back to life, and when it did the flashing glow plug light of doom was on. I was only 20 seconds from my house at that point so I pulled in, and the dial display (green one, not maxi dot) said 

‘ERROR STOP START’. Usually, the display says ‘STOP START NOT POSSIBLE’, although sometimes it does work. The car was running fine, no limp mode. Turned it off and back on, and there was no glow plug light but the stop start error was still on. I turned it off for a bit while I scanned it with the Carista, and it came up with codes :

15604- This came under the Engine category, but there was no indication of what the fault was, and google doesn’t seem to be much help either. 
00466 - Function Limitation due to under voltage

There was also the alarm horn and radio antenna ones which have always been there and are nothing new, but there was also a Left DRL fault code. The bulb light came on a little while ago, but then went away having turned the car on and off and all bulbs look fine. 
 

Other peculiar things that have happened recently are that once a few weeks ago while at a set of lights, the battery light came on and the idle dropped (sort of like it does when turning off the AC system. When this happened, I noticed that a faint whine that is audible when the car is running stopped, until the light went off again a few seconds later. This whine starts a few seconds after the engine has been started, and I think/hope that it’s a characteristic of the engine or regenerative system or something. 
The battery light came on again a couple of weeks ago for just a second. On both of these battery light occasions, there were no new fault codes.

 

I reset the codes today, and took it for a brief spin, no dash lights came on and no fault codes have come back, (other than alarm horn and radio ones). 
 

Any ideas about what could be going on? I find it strange that there are so many weird, random faults that seem to be occurring just once, then clearing themselves up almost immediately, and the fact that it came up with an unknown engine code is mystifying.

 

I was wondering if the battery could be on its way out?
 

I would have suggested the battery may be weak, if its still the original. Stop-start vehicles take a lot of battery power and need a stronger, more expensive unit so if replacing, do your homework to find a good deal but don't flimp. I would look for one with a nice long warranty as aftermarket batteries NEVER seem to last like the first, manufacturer fitted unit. May be due to them fitting higher spec or the simple fact that after nearly a decade, much of the components and wiring is now starting to offer more resistance.

I'll second the above that it's probably a weak battery. The electronic control modules in these cars go nuts when there isn't enough power coming from the battery. Make sure to get a stop-start compatible battery and find someone who can code it in (not sure if Carista can do this?).

24 minutes ago, chimaera said:

I'll second the above that it's probably a weak battery. The electronic control modules in these cars go nuts when there isn't enough power coming from the battery. Make sure to get a stop-start compatible battery and find someone who can code it in (not sure if Carista can do this?).

 

 

29 minutes ago, mrgf said:

I would have suggested the battery may be weak, if its still the original. Stop-start vehicles take a lot of battery power and need a stronger, more expensive unit so if replacing, do your homework to find a good deal but don't flimp. I would look for one with a nice long warranty as aftermarket batteries NEVER seem to last like the first, manufacturer fitted unit. May be due to them fitting higher spec or the simple fact that after nearly a decade, much of the components and wiring is now starting to offer more resistance.

Thanks for the replies guys, it’s in for an mot at a trusted garage, so I’ll ensure that a new compatible battery is put in. It’s a Yuasa one that’s in at the moment, am I right in thinking that they came with Varta ones from the factory?

Its possible that one that isn’t properly compatible was put in before I purchased it which could be why the stop start has always been reluctant to shut the car off. 
I’ll update with any more weird electrical chaos and the outcome once I know more

 

thanks

I don't have the stop-start tech on my model but from stuff I've read, the battery needs to be quite well charged-say 70% or so, in order to function properly.

3 hours ago, mrgf said:

I don't have the stop-start tech on my model but from stuff I've read, the battery needs to be quite well charged-say 70% or so, in order to function properly.

And that is what confuses me. Some days it behaves perfectly, even after just a short bit of driving, but other days, pulling up to a set of lights after a 30minute motorway journey it will not cut out. 
 

The battery was tested today, and it was fine, and the car has been behaving itself. I am feeling reassured, especially considering that it got a clean sheet on the MoT today, which I’m pleased about considering I’ve put 10,000 miles on since the last one! Unless some other strangeness happens, I’m putting it down to a glitch for now. Hopefully it keeps going as it is at the moment!