[phydor]

Hi there guys, is it something to do after disconnecting the 12 v battery without deactivating the HV system? 
I removed the battery and 24 hours later the car failed to start.
I left another i8 at the dealership with the same symptomps.The relevant error was DC/DC converter fault for the other one.
What could cause this to this one, just after removing the battery?

[phydor]

A guy came and started the car.I don't know how he made it, I suppose he performed that battery replacement procedure in ISTA.I was not there so I could see.He lied to my friend saying that he needs a new battery and he must carry on to reset things.

[phydor]

It seems that nobody knows about this issue.After disconnecting the i8's battery, the car starts to develop electrical errors.Basically, runs out of power while in rest mode.I searched for TSBs that imply that, nothing so far.I'm considering reflashing the EME, maybe that would change something.The car runs normally until it's left alone for a day or 2.Then, it won't start.

[phydor]

New update, if i delete the fault codes, the car starts normally, i don't know now for how long.I am starting to believe that something happens when you disconnect the battery without disconnecting the HV system.But nobody seems to know anything on i8 on this forum, so I gotta wait and see futher development.

[2013m5]

Here are the steps for your safety, when you’re working on HV system.
1. Make sure the hood or tail gate open. This is for access to HV service switch.
2. Wait for vehicle goes to sleep, or the START/STOP button light out.
3. Disconnect “switch off” the HV service switch.
4. Turn ignition and check the FLASH sign displayed on the instrument cluster/kombi.
If the FLASH sign not displaying, that meant the HV battery circuit still live, not safe to work on the HV system or vehicle.
5. If the FLASH sign is displaying, now you’re okay to disconnect the 12 volts battery.

Reverse the steps to turn vehicle system back on.

You must follow these steps. This will not create hard faults, or vehicle won’t start as same as your i8.

[phydor]

Here are the steps for your safety, when you’re working on HV system.
1. Make sure the hood or tail gate open. This is for access to HV service switch.
2. Wait for vehicle goes to sleep, or the START/STOP button light out.
3. Disconnect “switch off” the HV service switch.
4. Turn ignition and check the FLASH sign displayed on the instrument cluster/kombi.
If the FLASH sign not displaying, that meant the HV battery circuit still live, not safe to work on the HV system or vehicle.
5. If the FLASH sign is displaying, now you’re okay to disconnect the 12 volts battery.

Reverse the steps to turn vehicle system back on.

You must follow these steps. This will not create hard faults, or vehicle won’t start as same as your i8.

Mate, i know that, but why would it continue to throw errors?

[2013m5]

As I read post #1, the HV must be deactivated before 12 volts battery disconnect.
1. Did you have any USB device or Bluetooth OBDII adapter connected?
2. Is your 12 volts battery new And registered? and sometimes the new battery also battery bad because it’s not maintenance at dealer. This could cause the error “increased battery discharge when stationary”
3. Did you perform test plan for the DC/DC converter? What is the fault?

[inspi1981]

HV systém try charging 12V systém. There is no load so DC-DC convertor failed

[phydor]

HV systém try charging 12V systém. There is no load so DC-DC convertor failed

After deleting faults yesterday, no more faults on the car since.I'll wait a few days to see if the faults have really dissapeared.
Thanks guys.