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P85 unable to drive (12v no charge)

Hi ,

I have left one night my 2013 P85 on UMC charger all night. Next day afternoon I opened the door car sent many messages.. like car needs service unable to drive, 12v low, acceleration reduced, battery charging restricted, car will shut down etc...

After 1-2 mins car shutted down.. i was thinking 12v battery died.. i jump started it so at least car 2 lcds powered on but still error massages.. voltage in cigarette lighter was 11,8v so i left car on a 12v battery charger for a hole night to fill up 12v battery.. next day 12v was full.. voltage about 13v i made hard and soft reset. Car still giving same messages:(
Then i saw climate is on but blower not working.. also i checked voltage going down 12,5-12.2 so i guess dcdc converter not charging the 12v battery:(
SoC on big screen showing 0km but on the small lcd showing full charge..but with 340km (full should be 375km)
I left charge level set to 90% (340km)
Car before shutted says charging completed..

I have read many articles here with simular errors. But how to know is it the HV batt failure or DcDc converter, maybe HVJB fuse, or 12v battery it self? Maybe ac blower motor too.

Thanks for help!
Regs
Norbert
 

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The car will let the 12 volt battery discharge to a 50% SOC before it recharges it back to 100%. The last time I monitored this process, two years ago, it happened four times a day. You would need to monitor the 12 volt battery voltage over at least 8 hours to determine if the recharge by the DC to DC converter is working. I do this with a multi-meter, that has a USB interface to a computer, which gives me a graphic display of the voltage over time. If that recharge is not happening there are several possibilities. I don't know how to determine what the actual problem is.
 
Charger port shows red:(
No contactors sound so HV isolated..
I called Tesla SC they were very helpful.
They check my car online and maybe from the logs. They called me back after 2h said that HV battery dead.. and they ordered a new one.. as they get it will change the hole HV batt pack.. due car still under 8y warranty.. wow great service
 
Im experiencing similar issues. Everytime I schedule an appointment, drop the car off, wait for any updates from Tesla SC.. I generally wind up calling them for an update. They throw 12v batteries at this three times now. 1st one lasted 5months, the 2nd one lasted three weeks, this one has been just two weeks and same old problem. I even paid outta pocket for the entire MCU2 upgrade.. given the technician diagnosis a benefit of the doubt. This is supposed to be covered under the RECALL too. But I already spent over year with the shady software patches, motherboard, daughterboard, and SIM card changes. After Tesla SC went that route.. they then told me that I am not eligible for the RECALL for the MCU1 to be replaced. Thats how I came outta pocket -for the simple HOPE to get the car operating correctly- then I would argue the RECALL for the Safety Bulletin.
I almost forgot to mention. Since the MCU2 upgrade has been installed. When I enter my car, both screens generally stay blacked out/sleep mode I guess. I use the Tesla mobile app on my phone to determine my traveling speed. Something that I learned is that during the screens not operating or black out time, we also lose out function of the turn signals and hazards. Safety Issue for certain. Thanks to TESLA now I am on a similar road of malfunctions as before the MCU being replaced to the gen2.
 

SoCal Buzz

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Im experiencing similar issues. Everytime I schedule an appointment, drop the car off, wait for any updates from Tesla SC.. I generally wind up calling them for an update. They throw 12v batteries at this three times now. 1st one lasted 5months, the 2nd one lasted three weeks, this one has been just two weeks and same old problem. I even paid outta pocket for the entire MCU2 upgrade.. given the technician diagnosis a benefit of the doubt. This is supposed to be covered under the RECALL too. But I already spent over year with the shady software patches, motherboard, daughterboard, and SIM card changes. After Tesla SC went that route.. they then told me that I am not eligible for the RECALL for the MCU1 to be replaced. Thats how I came outta pocket -for the simple HOPE to get the car operating correctly- then I would argue the RECALL for the Safety Bulletin.
I almost forgot to mention. Since the MCU2 upgrade has been installed. When I enter my car, both screens generally stay blacked out/sleep mode I guess. I use the Tesla mobile app on my phone to determine my traveling speed. Something that I learned is that during the screens not operating or black out time, we also lose out function of the turn signals and hazards. Safety Issue for certain. Thanks to TESLA now I am on a similar road of malfunctions as before the MCU being replaced to the gen2.
If your screens are staying black for prolonged period after MCU upgrade, it should be covered under warranty.
 
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If your screens are staying black for prolonged period after MCU upgrade, it should be covered under warranty.
That will great. I'm super concerned for my low voltage 12v battery system. I don't understand why the technicians have not diagnosed and repaired this correctly yet. Can't drive the car with the 12 volt system failing. No MCU to run operations.
 
Im experiencing similar issues. Everytime I schedule an appointment, drop the car off, wait for any updates from Tesla SC.. I generally wind up calling them for an update. They throw 12v batteries at this three times now. 1st one lasted 5months, the 2nd one lasted three weeks, this one has been just two weeks and same old problem. I even paid outta pocket for the entire MCU2 upgrade.. given the technician diagnosis a benefit of the doubt. This is supposed to be covered under the RECALL too. But I already spent over year with the shady software patches, motherboard, daughterboard, and SIM card changes. After Tesla SC went that route.. they then told me that I am not eligible for the RECALL for the MCU1 to be replaced. Thats how I came outta pocket -for the simple HOPE to get the car operating correctly- then I would argue the RECALL for the Safety Bulletin.
I almost forgot to mention. Since the MCU2 upgrade has been installed. When I enter my car, both screens generally stay blacked out/sleep mode I guess. I use the Tesla mobile app on my phone to determine my traveling speed. Something that I learned is that during the screens not operating or black out time, we also lose out function of the turn signals and hazards. Safety Issue for certain. Thanks to TESLA now I am on a similar road of malfunctions as before the MCU being replaced to the gen2.
Try to wake up the car from the key or from the application as early as possible, this usually helps, the problem is not hardware but software
 
Im experiencing similar issues. Everytime I schedule an appointment, drop the car off, wait for any updates from Tesla SC.. I generally wind up calling them for an update. They throw 12v batteries at this three times now. 1st one lasted 5months, the 2nd one lasted three weeks, this one has been just two weeks and same old problem. I even paid outta pocket for the entire MCU2 upgrade.. given the technician diagnosis a benefit of the doubt. This is supposed to be covered under the RECALL too. But I already spent over year with the shady software patches, motherboard, daughterboard, and SIM card changes. After Tesla SC went that route.. they then told me that I am not eligible for the RECALL for the MCU1 to be replaced. Thats how I came outta pocket -for the simple HOPE to get the car operating correctly- then I would argue the RECALL for the Safety Bulletin.
I almost forgot to mention. Since the MCU2 upgrade has been installed. When I enter my car, both screens generally stay blacked out/sleep mode I guess. I use the Tesla mobile app on my phone to determine my traveling speed. Something that I learned is that during the screens not operating or black out time, we also lose out function of the turn signals and hazards. Safety Issue for certain. Thanks to TESLA now I am on a similar road of malfunctions as before the MCU being replaced to the gen2.
Let Tesla Sc check your HV pack. My HV batt was cotactors faulty. When car steady in garage you should hear a big click sound every 4-6h . That time contactors (big relay) connect hv batt. Dc/dc charger charges the 12v batt. You even should hear this big click when you open the car’s door . (Before that, car was sleeping)
 
Let Tesla Sc check your HV pack. My HV batt was cotactors faulty. When car steady in garage you should hear a big click sound every 4-6h . That time contactors (big relay) connect hv batt. Dc/dc charger charges the 12v batt. You even should hear this big click when you open the car’s door . (Before that, car was sleeping)
Yes. Thank you. I will make sure to listen for that each day too. I have heard those contactors click normally. I don't recall trying to listen for them today for example.

The low voltage system has to be functioning properly to allow the high voltage system to operate at full potential. The contactor is essentially a relay ..which is a simple on/off switch which uses low voltage/high amperage to function. So even if we have sufficient voltage on a 12 volt battery, but we don't have the amps aka CCA (cold cranking amps) then you have the poor performance result of a dead or bad 12v battery.

Even good technicians will over look this as a possibility of a 12v battery being faulty ..As soon as we see good 12.4 + volts. We tend to move on right away. I believe that is what's happening at the Tesla SC too.

Last appointment Tesla said they didn't find it. They told me the car is good for now, and for me to bring it back IF it does it again. I refused to take the car for the planned Christmas break drive down to SoCal.

In a few days Tesla had said they found the light/rain sensor located at the rear view mirror area was staying on and was drawing the battery voltage.

Without me knowing more of the electrical system.. that information sounded like a logical starting point. Move through the circuits one at a time and see what is staying on and drawing power or voltage. Then you compare the milliamps to the allowable measurement of the electrical diagrams to determine faulty or not.

I picked up the car. Within that week these battery fault code issues continued. I took it back to Tesla. I even approved them to change the MCU1 over to the MCU2 as a hope to just be done with the first gen mcu BS.. I was done with that systems antics. I really wanted the MCU2 to be the fix for everything that I had run into these past 18 months. We shall see.

The flip side to this can be a bad connector that plugs in -or- onto the relay or fuse or contactor. Electrical is not my strong point. In fact, it's truly maybe 2% of all mechanics that are hands down superb with electronics. These are the forever memorable guys that you may finally work with after maybe 20 years in the buisness. That is not me !
 
Yes. Thank you. I will make sure to listen for that each day too. I have heard those contactors click normally. I don't recall trying to listen for them today for example.

The low voltage system has to be functioning properly to allow the high voltage system to operate at full potential. The contactor is essentially a relay ..which is a simple on/off switch which uses low voltage/high amperage to function. So even if we have sufficient voltage on a 12 volt battery, but we don't have the amps aka CCA (cold cranking amps) then you have the poor performance result of a dead or bad 12v battery.

Even good technicians will over look this as a possibility of a 12v battery being faulty ..As soon as we see good 12.4 + volts. We tend to move on right away. I believe that is what's happening at the Tesla SC too.

Last appointment Tesla said they didn't find it. They told me the car is good for now, and for me to bring it back IF it does it again. I refused to take the car for the planned Christmas break drive down to SoCal.

In a few days Tesla had said they found the light/rain sensor located at the rear view mirror area was staying on and was drawing the battery voltage.

Without me knowing more of the electrical system.. that information sounded like a logical starting point. Move through the circuits one at a time and see what is staying on and drawing power or voltage. Then you compare the milliamps to the allowable measurement of the electrical diagrams to determine faulty or not.

I picked up the car. Within that week these battery fault code issues continued. I took it back to Tesla. I even approved them to change the MCU1 over to the MCU2 as a hope to just be done with the first gen mcu BS.. I was done with that systems antics. I really wanted the MCU2 to be the fix for everything that I had run into these past 18 months. We shall see.

The flip side to this can be a bad connector that plugs in -or- onto the relay or fuse or contactor. Electrical is not my strong point. In fact, it's truly maybe 2% of all mechanics that are hands down superb with electronics. These are the forever memorable guys that you may finally work with after maybe 20 years in the buisness. That is not me !
Did they check dc/dc charger condition? But as you say sure there should be stick realy that comsume 12v:(
I have another model s now. (70d 2016)
These days i just noticed there is hi vampire drain. 14km/day(24h)
 
Did they check dc/dc charger condition? But as you say sure there should be stick realy that comsume 12v:(
I have another model s now. (70d 2016)
These days i just noticed there is hi vampire drain. 14km/day(24h)
I dont believe them sometimes. Now I will ask for them to prove that what they inspected and tested. They don't like it when I do that.
 

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