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Discussion Starter #1
Today I got the Service Electric Vehicle System light on. I know it's common, but out of curiosity decided to connect AlfaOBD and look what's behind it.

Behind it was the P0A1F (Battery Energy Control Module), and the status was intermittent. I've erased the code with the AlfaOBD, but the light would stay up.

Tried a few key cycles, no difference. The car is driveable, it's accepting the charge well. The light is still on though.

So got the 10 mm wrench and disconnected the 12-volt. Connected it back after 10 minutes. Warning light is gone.

My guess is that the dash light status is stored separately from the battery management system, and this is erased on reboot.

The cause of the error itself, I believe was related to HV system cooling. It's +36C today (97F), and we turned on the AC while the vehicle was charging, to precondition the cabin.

My wild guess is that the cooling system could not keep up and threw an error somewhere.
 

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Thanks for the report.

That last guess is a bit too "wild" for me. Unless there's something wrong with the HV batt cooling system, I VERY strongly doubt it was maxed out.

One time with 113F on the display during L2 charging right after driving my friend's 500e, the radiator fan was still inaudibly slow (maybe even stopped), & the loud A/C compressor didn't even self-activate at all for HV cooling. Adding cabin A/C drain while charging actually lowers the current going into the HV batt, thereby reducing the need to cool it.

I think there may be a way to check the last few peak batt temps in AlfaOBD.

Depending on your version of "a few", it's supposed to be 5 key cycles to clear codes, so 4 would have been insufficient even if 5 would have worked.
 

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I think there may be a way to check the last few peak batt temps in AlfaOBD.

Depending on your version of "a few", it's supposed to be 5 key cycles to clear codes, so 4 would have been insufficient even if 5 would have worked.
I've checked the AlfaOBD log and the batt temp was the highest today - the balance board was indicating 43C; by the way, the hardcoded HV battery alarm temp is 55C.

This log is very convenient - you can export it and compare all the values between different measurements, which I'm now trying to do. One thing I noticed in the file this time was the higher temp (which somewhat coincided with the moment when the message was activated - just after the AC was turned on during charging; charging was started after the car sitting in sunlight for a few hours).

There were 7-8 key cycles all with the key being taken out. I'm not sure if I was waiting for the screen to go black though.
 

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Discussion Starter #4 (Edited)
And here's the spreadsheet (tab delimited export from Excel, the forum wouldn't allow XLSX upload) - gives a little insight on what is changing in the battery and what is not (the log entries are over 5000 km). I still tend to think this was related to temperature.

108885
 

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Discussion Starter #5
Yesterday I spoke with our neighbors' kid who's now building an EV and studying to become an EV mechanic.

Coincidentally, his first suggestion also was that the error code might be caused by high temperatures, as the A/C heats up the radiator which reduces the efficiency of battery cooling. So when the car is stopped, it all comes down to the efficiency of the combination of fans and radiators, and the sensitivity of battery management system.
 

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2017 Fiat 500e (Billet Argento), 2015 VW Golf Sportwagen TSI 5MT (Tungsten Silver), 2002 Honda VFR
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Ive never had any faults like that and it gets way hotter then that here on the regular. Ive been sitting at a L2 before when it was 115 outside with my AC powered up napping in the car, its been totally fine. I also been napping on lunches at work when its 110 at times on a 110v charger and still been fine.
 

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Well it's obvious that this error does not come up every time when the weather heats up. I'm just trying to say that it might somehow be related to the higher temperatures.
In the log, I have the time when the code was registered, and this was several moments after the car was plugged in into L2 for a few minutes, and then the "ignition" was turned on with A/C.
This also coincided with hot weather, car sitting in the sun and the highest logged balance board temp (which all are still below the HV alarm temp).

If you look at the HV stats above, it seems quite interesting. How realistic is that during the first 4 years (first 3 being in California), the battery only clocked 350 mins in 30..40C (86..106F), and there's another 1200 mins in the last month alone. I'll have a look at the fan - maybe it's something physical.
 

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Discussion Starter #8
So the fans are intact, the A/C compressor is vibrating happily.
On L2 charge at 24C the system maintains a loop of 30 sec fan silence, then 8 seconds run time.
 

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Our HV cooling system seems VERY powerful, not even needing the rad fan (on L2 at 45C/113F) let alone A/C chilling. At only 24C/76F my fans never come on, so yours must have had the key "on" & A/C manually activated.

With your batt temp staying well below critical, your initial issue may have just been a random glitch. In nearly 5 years of ownership I have seen a few error messages, & while some I consider user error (like shifting between R & D while still barely moving), others seem to randomly occur rerely at startup, as with other computers I've used.

All of MINE were corrected by cycling the key to fully black screen less than 5 times, however the latter is reportedly required to clear some error codes that are more stubborn than I've had.
 

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Discussion Starter #10
They key was out during charging. This looks to be normal charging behaviour in warmer weather (the radiator fans aren't running at full speed, so usually you won't hear them; the cabin fan is the loud one). They turn on regularly though.
 

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So the fans are intact, the A/C compressor is vibrating happily.
On L2 charge at 24C the system maintains a loop of 30 sec fan silence, then 8 seconds run time...
They key was out during charging. This looks to be normal charging behaviour in warmer weather (the radiator fans aren't running at full speed, so usually you won't hear them; the cabin fan is the loud one). They turn on regularly though.
It seems to me like something might be a bit out of whack. On L2 at only 24C (76F) my rad fans are always silent* (unless I manually turn on A/C), & my A/C compressor stays off.

In fact, with A/C off my rad fans have only been audible* momentarily 3 times when plugging into L2 right after driving in over about 30C (86F). The A/C compressor didn't even come on when I did that when the display showed 113F (45C).

In case anyone's understandably thinking it's MY car that's faulty, the last time I heard my rad fans on L2 I monitored OBD & HV temp peak was only 1 degree over ambient.

* They sometimes spin too slow to hear, even with the hood open & very low background noise.
 

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Yesterday I spoke with our neighbors' kid who's now building an EV and studying to become an EV mechanic.

Coincidentally, his first suggestion also was that the error code might be caused by high temperatures, as the A/C heats up the radiator which reduces the efficiency of battery cooling. So when the car is stopped, it all comes down to the efficiency of the combination of fans and radiators, and the sensitivity of battery management system.
That kid knows what he is talking.. :)
 

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I've had my fans come on two occasions during the last week after coming home (uphill drive), parking in the garage (which is in the afternoon sun) and having to charge right away for an evening trip. Ambient around 32-34 C. Level 1 charging. Don't know if the compressor comes on, but the fans are very audible. I figured it was just the battery management doing its thing to protect the HV battery. It does keep running in the loop fiatatat describes. I think this is normal North of 60 :sneaky:
 

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Thanks for the report, but that "60" must be a typo, because my rad fan is sometimes momentarily audible North of 90 (F) or 30 (C), but never at 60F (16C).

My garage is always North of 60F, average probably around 70F (21C) & on L1 no fan is ever audible.

Yes, it seems to be the battery management doing its thing to protect the HV battery.

Yes the rad fans are often very audible BUT also often spinning nearly silently at a lower speed.

Same for the A/C compressor, which is so audible at peak level it has prompted user concern, but it too cycles to lower levels quieter than the rad fan on high

It also cycles to a full stop but you can tell if it's been on by feeling it (driver's wheelwell) or one of its cooled metal pipes under the hood.
 
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