Rav4EV4me
Member
Starting a new post here, which is essentially a continuation of my post in the Off-Topic area and will hopefully answer a few question asked by alflash.
Let me first explain the run-up to the problem.
I was driving the car running errands one day. When I came out from one of the stores to move on to the next errand, I was able to start the car, however, the car would not go into drive or reverse. Moreover, the “Check EV System” message appeared on the console. I did not notice any different sounds or other signals prior to that that would have indicated a problem.
For the next couple hours, I was able to turn the ignition on and off successfully until the car was towed to the dealer that night.
Let me also add that this car does NOT have any special additions or modifications like the JdeMO fast-charging upgrade. It is effectively stock.
Once the car was at the dealer, there was no issue turning the car on and rolling it in neutral to get it off the flatbed truck. Before leaving the dealer, we tried to move the car one more time to position more completely in a parking space. Before I was able to turn the car back off, the console lights flashed on and off several times, then began flickering as if the voltage was low. At that point, I was unable to power the car off. After several minutes and attempts, I had to leave the car and go home. Effectively, the car was still on. At this point, the dealer was closed and I would pick up the issue in the morning.
I explained to the dealer what had been going on, including the flickering. While I am reasonably certain the 12v battery was not the problem, The next few paragraphs will go on to document what the Toyota mechanic wrote on my service form.
Now keep in mind, I had explained to them that the battery was fine until the point of the problem manifesting itself the prior day. However, they seemed to have been fixed on the 12v battery being the problem, not a symptom. The technician continued.
Obviously, they had left it parked where I had towed it and were doing their diagnostics outside. Finally the technician wrote:
Let me add that, yes, I was fully aware of the rareness of this car before purchase. While I owned it, I deliberately took it in for “maintenance” several times so there would be a record of my car on file with the dealer. While they never performed any “service” to the HV Battery, the car wasn’t that “new” to them.
So, the above language is the notation from the dealer. Following that series of service actions, I towed the car back home, as the dealer did not want the car at the dealership while waiting for the backordered, “no eta” part. Nor did I. That was in May 2023. The car has been in my driveway ever since. I keep the 12v battery on the bench to prevent the car from killing it. I have moved it once and know that I can pop the battery in and shift it into neutral without issue. I have not tried charging the car.
With everything mentioned above. Any other insights on what I can do from here? Thanks.
Let me first explain the run-up to the problem.
I was driving the car running errands one day. When I came out from one of the stores to move on to the next errand, I was able to start the car, however, the car would not go into drive or reverse. Moreover, the “Check EV System” message appeared on the console. I did not notice any different sounds or other signals prior to that that would have indicated a problem.
For the next couple hours, I was able to turn the ignition on and off successfully until the car was towed to the dealer that night.
Let me also add that this car does NOT have any special additions or modifications like the JdeMO fast-charging upgrade. It is effectively stock.
Once the car was at the dealer, there was no issue turning the car on and rolling it in neutral to get it off the flatbed truck. Before leaving the dealer, we tried to move the car one more time to position more completely in a parking space. Before I was able to turn the car back off, the console lights flashed on and off several times, then began flickering as if the voltage was low. At that point, I was unable to power the car off. After several minutes and attempts, I had to leave the car and go home. Effectively, the car was still on. At this point, the dealer was closed and I would pick up the issue in the morning.
I explained to the dealer what had been going on, including the flickering. While I am reasonably certain the 12v battery was not the problem, The next few paragraphs will go on to document what the Toyota mechanic wrote on my service form.
Verified vehicle is completely dead, does not power up at all. Connected jump pack and vehicle powered up. 12v battery is dead. Connected Techstream and found stored code P312F Electric Propulsion Control Module. Vehicle will not start and code will not clear. Vehicle has a second OBD2 connector in the left rear of the vehicle for the Tesla side of the system. We need to check the codes on the Tesla side. This requires downloading the Tesla Software off TIS and connecting to rear OBD2 using Tesla Integration Cable. We know the 12v battery is dead, my thinking is that there are codes stored on the Tesla side from the dead 12v battery that need to be cleared for the P312F to clear and allow Ready On. The codes may be just a result of the dead battery or there may be a larger issue.
Now keep in mind, I had explained to them that the battery was fine until the point of the problem manifesting itself the prior day. However, they seemed to have been fixed on the 12v battery being the problem, not a symptom. The technician continued.
Either way, we need to start by assessing the Tesla side and seeing what we find. Cable was brought to us and, and new 12v battery installed. P312F will not clear on Toyota side. Connected to Tesla side of vehicle and ran “Alert History Log” for the last 2 weeks. All alerts have been resolved besides BMS f061 HV Battery 12V Power Supply Problem Detected, which reads as ‘ongoing’. Updated to TAS case. TAS agent stated to proceed with troubleshooting chart of BMS f061 Tesla code which consists of checking all power grounds to EV Battery ECU. Once testing was completed TAS agent stated to call back and follow up with results. Accessing the connector needed for testing, which is located on the EV Battery requires removing battery shields beneath vehicle to perform pinout checks. At this point now will probably need to get the vehicle moved into the shop and onto a lift to be able to deal with these shields and gain access.
Obviously, they had left it parked where I had towed it and were doing their diagnostics outside. Finally the technician wrote:
Hopefully customer is aware that this is a rare vehicle with both Toyota and Tesla equipment and diagnostic tools/reference materials so it is taking some time to sort through it all between waiting for cable and multiple calls to TAS, etc as well as the learning curve of the Tesla diagnostic equipment. Proceeded through electrical pinout tests for BMS f061 code as outlined in repair manual. Testing found short to ground on battery voltage supply side of harness. With fuse removed there is no longer any short on harness/EV Battery ECU side. Short remains on power supply side of battery. Fuse is fed from DC/DC Converter. Disconnected harness at DC/DC Converter and short circuit no longer present. Short is internal to DC/DC Converter. TAS agent stated there are other known instances of BMS f061 code and failure to Ready On caused by internal short of DC/DC Converter, replacement recommended. Part is on backorder, no eta.
Let me add that, yes, I was fully aware of the rareness of this car before purchase. While I owned it, I deliberately took it in for “maintenance” several times so there would be a record of my car on file with the dealer. While they never performed any “service” to the HV Battery, the car wasn’t that “new” to them.
So, the above language is the notation from the dealer. Following that series of service actions, I towed the car back home, as the dealer did not want the car at the dealership while waiting for the backordered, “no eta” part. Nor did I. That was in May 2023. The car has been in my driveway ever since. I keep the 12v battery on the bench to prevent the car from killing it. I have moved it once and know that I can pop the battery in and shift it into neutral without issue. I have not tried charging the car.
With everything mentioned above. Any other insights on what I can do from here? Thanks.