Truck Broke (HVBATT_a011 & HVBATT_a174 Alerts) - RESOLVED - Truck Fixed

[Jager]

Yesterday, my four-day-old CT terminated charging (L2, at home) unexpectedly, with HVBATT_a011 (Vehicle may not restart; Service is required) and HVBATT_a174 (Unable to charge; Disconnect and retry) active alerts. Walking out to the vehicle, the charge port light was solid red.

I soft rebooted the vehicle (the two scroll wheels). The two active alerts cleared (vehicle displayed "There are no active alerts"). Unplugged the charge cable. Plugged the charge cable back into the charge port. The vehicle then completed its charge with no problems.

A short, ~20-mile test drive was uneventful.

Another short L2 charge today completed uneventfully. As did another ~20-mile drive.

I have a service appointment on 7/30/2024 at the Tyco Road (Virginia) Service Center. That was the earliest available date.

Recent build. 19xxx VIN. AWD.

Anyone have any insight into those two error codes?

Sponsored

 

[Jager]

TLDR: Things quickly deteriorated after the post above. Truck was well and truly broken. The Service Center replaced the rear drive unit and all is now well.


Here's the high-level summary:

• Day 4 (post truck delivery). 359 miles. Truck unexpectedly terminated charging. Kicked out codes HVBATT_a011 (Vehicle may not restart; Service is required) and HVBATT_a174 (Unable to charge; Disconnect and retry). Soft reboot cleared. 20-mile test drive was uneventful. Scheduled service for 15 days later (earliest available service slot).
• Day 10. 741 miles. Phone app would not connect to vehicle. Walking out to the truck, found it totally unresponsive. Doors would not open, even with key card. Truck dead, and locked up tight as a drum. Jumped truck with an ICE vehicle. Alerts: TAS_a313, PSFA_a178, RSA_a211, RSA_a210, VCLEFT_a220, VCLEFT_a402, HVBATT_a120, HVBATT_a174, HVBATT_a011.
• Day 20. 903 miles. (Morning of service appointment). Reprise of event on Day 10.... phone app would not connect to vehicle; vehicle totally dead and unresponsive to key card. Jumped with ICE vehicle. Numerous, very serious alerts, including Loss of System Redundancy, which prevented driving except via override, which allowed moving at very low speed to move vehicle in position for transport. Anticipating that the vehicle might need to be towed, I moved it slowly out of its parked position, lining it up straight on the driveway. Then exited the vehicle, walked away, gave it a minute or so to reset itself, and then walked back out. At that point the door could be opened via phone key, and when the brake pedal was pressed, came to life normally. At this point I was able to drive it to Tyco Rd for the service appointment.
• Days 20-27. 940 miles. In service. A Model Y loaner was provided.
  • Day 1 in service. 940 miles. The estimated time of completion was 5:30pm that same day. Late in the afternoon I received a message that the repairs would take additional time; and the estimated time of completion was changed to 5:30pm the next day.
  • Day 2 in service. 940 miles. In the middle of the afternoon I received a message in the app that the rear drive unit would need to be replaced. The estimated time of completion was moved out another day, to 5:30pm.
    
    I messaged back my thanks for the update; and asked for clarification regarding the ETA (since I was a little bit surprised that they would have spare drive units on hand in the service center).
    
    A few minutes later, after thinking more about the drive unit replacement, I messaged back a second question, pointing out that the three failure events had all occurred while the vehicle was parked, and asking how a quiescent, non-powered drive unit might cause them.
    
    No response to either of those questions during the remainder of the day.
  • Day 3 in service. 940 miles. Shortly after 9am I checked the app and noticed that the ETA for completion was moved out one more day, at 4:00pm.
    
    No message otherwise (or answer to my questions posed the previous day).
    
    
  • Day 4 in service. 940 miles. At 1:50pm they messaged me that they weren’t sure why the failures occurred, and were still diagnosing it. They bumped the estimated completion out another (business) day, at 4:00pm. I thanked them for the update.
    
    Perhaps of interest, I checked the app numerous times (probably once an hour) since I dropped the vehicle off to see if there was any kind of update. Almost every time, the app showed a simple graphic of a Cybertruck sitting quietly, parked. All closed up.
    
    Yesterday, on day 3 in service, on one occasion when I checked the app the graphic showed the Cybertruck, but with the frunk and the front driver-side door open. It was open for maybe an hour. Two at the most.
    
    And today, just a moment before I received their 1:50pm message, I saw the same frunk-and-door-open graphic.
    
    If the app graphic is accurate with respect to doors and frunk being open, it would strongly suggest that they have not spent much time physically working on the vehicle. It’s hard to imagine much troubleshooting or repair that might be done without the frunk and/or one or more doors being open.
    
    2:56pm. App shows frunk and both driver-side doors open.
    
    3:23pm. App shows all doors and frunk closed.
  • Day 5 in service. 940 miles. Weekend.
  • Day 6 in service. 940 miles. Weekend.
  • Day 7 in service. 940 miles.
    9:55am. App shows frunk and driver door open (had been closed earlier).
    
    10:38am. App shows vehicle being driven. Mileage at 942, and increasing. Appears to be a road test?
    
    10:40am. Vehicle is stopped. Mileage at 944.
    
    11:45am. App suddenly showed “repair complete.” Mileage at 949 (so apparently another quick road test).
    
    2:00pm. Began driving loaner to Tyco Rd., even though the paperwork had not come through yet (the app was not saying to pick up vehicle). Around 2:45pm, shortly before I arrived, the text came through that the vehicle was ready for pickup. Parked the loaner; confirmed through the app that the Cybertruck was ready to be picked up. Not a lot of detail other than that they replaced the rear drive unit due to “low isolation resistance” and performed an alignment.
    
    Uneventful drive home. The truck drove and felt great.
    

 

[Jager]

It's been 12 days since picking up from service. Truck now has 1812 miles on it - roughly double what it had when I took it in to service - and has been perfect. I wanted to wait until it had enough time and miles post-service before posting this update.

Two small road trips, three Supercharging sessions, and one little off-road adventure later, I'm confident in now reporting that everything is copasetic. The Cybertruck rocks like few things I've ever owned.

Tesla service was a bit of a mixed bag. Getting an appointment took longer than it should have. And communication from Tesla while my vehicle was in for service was pretty poor. But they did provide me with a loaner, which was immensely helpful in navigating the logistics of getting my truck to the SC. They apparently had the replacement rear drive unit on hand, which I would not have expected. And they clearly nailed the diagnosis.

The truck has been perfect since.

 

[mongo]

A few minutes later, after thinking more about the drive unit replacement, I messaged back a second question, pointing out that the three failure events had all occurred while the vehicle was parked, and asking how a quiescent, non-powered drive unit might cause them.

The Cybertruck basically has one common high voltage bus. A failure of any component directly on the bus can cause it to isolate the pack. That could terminate a charging session and prevent maintaining the 48V battery.

The HV connections are accessible from under the vehicle so they can check for faults in drive units and the HVAC compressor fairly easily.

Sponsored