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Electron Summit White NK13...110k 92.7 and rising
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Discussion Starter · #1 · (Edited)
So this is mainly another shout-out for Bellinger at Grove (Wantage), especially service manager Alan, workshop manager Steve and technician James; although I hope it may also be a useful diagnostic aid for someone in the future.

For a year or more I've been having occasional charge failures. The Rolec drops out immediately on connecting and the car displays Not Able to Charge. On starting up, the battery is completely disconnected with zero range, the engine generator starts, display shows Propulsion Power Reduced and the car runs only on that with no access to the battery buffer. Drive a short distance, stop and re-start and the car returns to normal behaviour, the GOM goes a bit haywire but slowly returns to normal, MIL illuminates. And that was it.

The problem became steadily more frequent and a code P0AF8 started to show. I was unable to clear this as it sets HV codes that only the sophisticated GM equipment can get to.

Initial diagnosis was inconclusive as clearing the codes (always the first step) left the car working normally and suspecting the Rolec charger (until three days after I got home). I live 100 miles from Bellinger by the way.

So after discussion with them I started to create detailed logs of the problem (see attached) and eventually the fault went 'hard' in January and I booked it back in at the beginning of Feb.

P0AF8 is an odd code. The test is for a voltage drop between the HV battery and the next module. So if you are trying to drive that is the main lines to the HPCM2 invertor, and if you are trying to charge it is the lines to the on-board charger. So you need to know the context where the fault is happening and also that explains why a fault triggered by charging will get cleared by then running the car.

I had a fault while charging. The charging circuit includes the charge port, the on-board charger (in front of the O/S front wheel), and the HV battery. The service manuals says do the following: (1) check all the wiring and connections for continuity; if not that then (2) change the charge port; if not that then (3) change the on-board charger; if not that then (4) change the HV battery :oops:

The wiring checked out Ok and I'd replaced the charge port last year so we skipped that. A new on-board charger is £1500 and fitting another £300. Bellinger were happy to fit a used on-board charger if I could find one and gave me the part number. I did find one in NW USA for $500. With shipping and import duty it came to £750. Took a few weeks to arrive at Bellinger and they fitted it a couple of weeks ago. Seemed to solve the problem and they then (at my request) used it as a camp taxi for ten days racking up 350 miles and charging it as often as they could. I collected it today and its now home and happily charging.

Just so lucky it wasn't the relay block in the HV battery. I found a post in the US thread where the same (rare) fault was NOT fixed by changing the charger but WAS by changing the HV battery. Seems it could be either.

The guys at Bellinger commented on how useful it was to have the detailed fault information as it was the first time they had seen this. They sometimes get partial/misleading descriptions apparently and it was probably fortunate that its not my only car so I could leave it with them (for two months in fact) and not be badgering to get it back by 5pm. Also, while they were driving it they spotted a clicking from the drive shaft so that got all sorted out as well.

I really do recommend Bellinger as I find them genuinely still enthusiastic about Amperas despite no longer being VX dealer - and the fact that they will stick at a problem (if you give them space) and work with you on an economical solution just makes the 200mile round trip worth it for me.

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Electron Summit White NK13...110k 92.7 and rising
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Discussion Starter · #2 ·
Well, it's back :mad:

After running and charging faultlessly throughout April, suddenly the overnight charge on Thursday failed and P0AF8 is showing again.

Weirdly, I was able to clear the code this time and when I went to Tesco yesterday I tried it on the Podpoint not expecting anything, and it charged. Got home and it failed again. Cleared the codes again today and went to Tesco again - this time it failed.

Two+ possibilities:
  1. My secondhand on-board charger has developed the same fault as my original one - (hmmmm really??)
  2. It's the HV battery (or rather the interface with the relays) and it never was the charger
  3. Or something else really weird....
Guess I'm just unlucky. Fingers crossed used car prices continue to rise to make fitting a replacement battery financially viable :ROFLMAO: A few months ago it would have been an easier decision, with the price of a new battery being more or less the same as binning it and buying another.

The guys at Bellinger have been super helpful as always but there are limits to what good intentions alone can achieve.
 

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Sorry to hear that the problem has returned. Intermittent problems are difficult to diagnose.
Are you able to drive the car in mountain mode and see if the battery charge increases? If so the battery contactors are OK.
You can also check the voltages of the 96 cell groups using the MGV application. This may providea clue about the battery health.
Alternatively do you keep the diagnostic dongle plugged in all the time? This can sometimes give problems with spurious trouble codes if the 12v battery is on its way out. I had several error codes including propulsion power reduced etc.when the dongle was left plugged in and battery power drained below 12v.
 

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Electron Summit White NK13...110k 92.7 and rising
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Discussion Starter · #4 ·
Thanks for that. The car drives perfectly and yes I do use MM to keep the battery at the 50% mark.

I do tend to leave the dongle in so that's good advice about unplugging. But I don't think it's relevant to my particular problem only because it started happening last year before I got a dongle.

What really puzzles me is the intermittent nature. This has been going on for 6 months now on and off. Most recently, after fitting a replacement on-board charger, there were no problems for month, then the same failure again with the same code, then after clearing the code it charges once at Tesco - then fails again at home, then clear the codes again and try Tesco again and it fails. Still fails at home.

Intermittent faults usually point towards some sort of continuity issue - corroded contacts or faulty cable. But Bellinger say they inspected all of that carefully and found nothing. I still think it may be significant that it did work after all the cables were remove and refitted (as well as changing the charger of course) and now it doesn't. I'm going to have a close look at the contacts on the old charger to see if there is any grunge. It is in a rather exposed position.

I also think that it might be the relay in the battery. But AFAIK the relays for charging are not the same as the ones for normal driving (and regen/MM/Hold). So the fact that it drives OK does not mean that the charging relay is not the problem.

The diagnostics are rather weak in this area. There are no specific diagnostics run on the battery interface. the only test that runs is to measure a voltage difference between the relay and either the on-board charger OR the invertor depending on whether you are charging or driving. If charging, it can be the wiring, the charger or the HV battery - and the procedure simply says check and replace each in turn until the fault is fixed !! Worst case, you'll get through £10,000.

The real tragedy is that here in the UK, insurance and corporate H&S means that franchised garages are not authorised to carry out repairs for which they do not have instructions and training. It's not quite the same in the US. Here in the UK, there are no instructions for opening up the battery and replacing the interface panel at the front where the relays are. And if anyone else does it, unless they can demonstrate that it has been done to the required standard, they won't touch it either. I'm not convinced that a HEVRA garage would behave any differently.

So if it IS the relay, for the price of a $500 interface panel (or worse a $50 relay), the owner has to foot a bill of say £7000 for a new battery, when there is nothing wrong with the battery itself.

But for now the problem is just working out where the problem really lies. Next step is to go over the Bellinger and get the codes cleared (including the HV ones that are not accessible via TorquePro) and see if that gets it charging again.
 

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Electron Summit White NK13...110k 92.7 and rising
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Discussion Starter · #6 ·
Hi - I have P0AF8 and P0ABC and it happens occasionally. Did you ever get yours sorted? Grateful for any advice. Have had the charge port replaced a few years ago
Hi -yes it was sorted eventually - took about 9 months though, during most of which I did not have the car!

See this thread for the dénoument: P0AF8 - Not able to charge. Some lessons learnt.

Your additional code (P0ABC) is an additional but related diagnostic though -"The battery energy control module detects the terminal voltage is less than 24 V on the battery side of the main contactors ". The BECM is part of the same module I had replaced - its enclosed in the black plastic box at the rear of the BBDU. To me it all sounds like a failing battery charging relay - just like mine.

Best of luck.


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Hi -yes it was sorted eventually - took about 9 months though, during most of which I did not have the car!

See this thread for the dénoument: P0AF8 - Not able to charge. Some lessons learnt.

Your additional code (P0ABC) is an additional but related diagnostic though -"The battery energy control module detects the terminal voltage is less than 24 V on the battery side of the main contactors ". The BECM is part of the same module I had replaced - its enclosed in the black plastic box at the rear of the BBDU. To me it all sounds like a failing battery charging relay - just like mine.

Best of luck.


View attachment 169441
thank you. I'll start the process. Right now the fault is intermittent and quite annoying. Car is just out of warranty so will see how much it costs. Seems to only happen in the damp.
 
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