new 12v dying, bms fault, dcdc intermittent cycle

[Jlahrens30]

2015 p85d
BMS_f150_SW_precharge_too__long
BMS_f073_SW_Unexpectd_HV_Sys_Bhvr

in the beginning: dreaded car may not start next time...SC replaces drive unit. 3 days after getting the car back... similar message. AND 12V is about dead. SC wants their pound of flesh and wants to charge diagnostic fee; lets change the battery heater for 1000...

I replace the battery and battery heater, similar error messages. cid dev chg screen shows battery voltage about .4v lower than voltmeter: replace IBS...

maybe a bad fuse or open switch in the front hvjb? i pull a houdini and pull the front hvjb... all 4 fuses have continuity...

obtain some hvil data:

bms hvil voltage 5.94v.
master hvil charger 4.76v
slave hvil charger 3.53v

the dcdc cycles intermittently. when it cycles on, the gremlins go away. otherwise the 12v dies and i get the faults:

BMS_f150_SW_precharge_too__long
BMS_f073_SW_Unexpectd_HV_Sys_Bhvr

if the bms is in fault state, the car can't charge, when the dcdc cycles, bms goes to support mode and i can charge. car has dual chargers...i an able to charge at 80a with dcdc active.

...help?

 

[KyleDay]

What battery did you replace your old 12v with?

These are the corresponding configs you need to set depending upon what version of the 12v battery you installed so that your dcdc inverter charges the right chemistry-

Exide: 0
CnD: 1
CnDNanoCarbon: 2
AtlasBX: 3
Sebang: 4
AtlasU1AGM: 5

 

[Jlahrens30]

new from sc, i believe its CnDNanoCarbon, tan and black. I'll update config, but didn't think that would be the continual cause but rather, why the battery could have a shorter than anticipated life expectency

 

[KyleDay]

I agree; but can't hurt.

There's an lvs value for 12v current and charge status (I don't remember it off the top of my head). Run

Lvs | grep -i 12v

And do you learn anything interesting?

 

[Jlahrens30]

i have to get tge dcdc back in. what a pita. I'm guessing tesla drops the bat to mess with it. from the top, i need an army of mini soldiers to button it up.

on another note, while redeploy successfully stages, the updates have consistently failed

 

[demundus]

i have to get tge dcdc back in. what a pita. I'm guessing tesla drops the bat to mess with it. from the top, i need an army of mini soldiers to button it up.

on another note, while redeploy successfully stages, the updates have consistently failed

ive never cursed more in my life than when i replaced my own 12v without dropping the DCDC. second only to... dropping the DCDC. Third only to getting it back in. good luck

 

[KyleDay]

i have to get tge dcdc back in. what a pita. I'm guessing tesla drops the bat to mess with it. from the top, i need an army of mini soldiers to button it up.

on another note, while redeploy successfully stages, the updates have consistently failed

Well that's why your 12v keeps dying. If your deploys don't succeed gateway won't let contractors close to charge 12v

 

[Jlahrens30]

Well that's why your 12v keeps dying. If your deploys don't succeed gateway won't let contractors close to charge 12v

would the dcdc intermittently cycle along that line of thinking?

and death by a million little scapes and cuts...the dcdc is back in

 

[KyleDay]

would the dcdc intermittently cycle along that line of thinking?

and death by a million little scapes and cuts...the dcdc is back in

Dcdc may cycle I guess, but it won't get any feed because contractors won't close until you deploy successfully

 

[aerodyne]

I replaced my 12v with same part number in April when I noted car staying awake more. Load testing revealed 18 out of 33 AH left on old batt.

A month later, had similar problems to the OP. SeC said contactors failed in the HV pack.

I never did any programming, just powered down the car and swapped Batts.

 

[demundus]

Dcdc may cycle I guess, but it won't get any feed because contractors won't close until you deploy successfully

Cant you force them to close with a voltage jump, like a burst from a trickle charger? Regardless of gateway connection.

 

[KyleDay]

Cant you force them to close with a voltage jump, like a burst from a trickle charger? Regardless of gateway connection.

No. And that'd be a very bad idea

 

[Jlahrens30]

Dcdc may cycle I guess, but it won't get any feed because contractors won't close until you deploy successfully

guess the next objective is to get the firmware to redeploy. im on 2020.24...i think i tried to update to .40 and that failed a while ago.

 

[Jlahrens30]

service center replaced bms; car worked great from Friday to Wednesday...new bag of goodies:

BMS_w008_HW_HVIL
DI_w086_hvilNotPresent
DIS_w086_ hvilNotPresent
CHG_w034_swHVIL
DIS_w166_hvilOutOfBounds
CHGS_w034_swHVIL
BMS_w044_SW_Assertion

...car may not restart...

 

[cloneguru]

service center replaced bms; car worked great from Friday to Wednesday...new bag of goodies:

BMS_w008_HW_HVIL
DI_w086_hvilNotPresent
DIS_w086_ hvilNotPresent
CHG_w034_swHVIL
DIS_w166_hvilOutOfBounds
CHGS_w034_swHVIL
BMS_w044_SW_Assertion

...car may not restart...

Do you recall what happened after this?