Hi. Driving home in New Orleans with wife, 2 dogs and frozen groceries, and our 2012 Prius v (110k miles) suddenly engaged mush pedal. The brake system light and hybrid system light came on. I tried to make it home but then the steering light came on. I had to pull over to look at the manual. I made the mistake of turning the car off, and then it would not engage Drive from park. So we had the car towed to the stealer and cabbed it home. I don’t have a diagnostic unit. If I had time to read this forum I probably would have tried disconnecting / reconnecting the 12v just to get home and then gotten a diagnostic. Obviously unrelated systems point to computer or hybrid battery. I will ask the stealer for a complete diagnostic readout but do you have any advice on what to watch out for? Diagnostics for each cell?
Hi. Driving home in New Orleans with wife, 2 dogs and frozen groceries, and our 2012 Prius v (110k miles) suddenly engaged mush pedal. The brake system light and hybrid system light came on. I tried to make it home but then the steering light came on. I had to pull over to look at the manual. I made the mistake of turning the car off, and then it would not engage Drive from park. So we had the car towed to the stealer and cabbed it home. I don’t have a diagnostic unit. If I had time to read this forum I probably would have tried disconnecting / reconnecting the 12v just to get home and then gotten a diagnostic. Obviously unrelated systems point to computer or hybrid battery. I will ask the stealer for a complete diagnostic readout but do you have any advice on what to watch out for? Diagnostics for each cell?
A couple of coincidental possibilities there.... Has the motor-generator/ECU TSB been accomplished? https://static.nhtsa.gov/odi/rcl/2015/RCMN-15V449-4175.pdf There is also a TSB and warranty extension on the brake accumulator/ABS pump that may be relevant. https://static.nhtsa.gov/odi/tsbs/2020/MC-10181800-9999.pdf
If you had time to read this forum, you'd also have known not to jump to "obviously unrelated systems". The systems in the car communicate and coordinate with each other, including about diagnostic codes, and they often post trouble codes and warning lights in matched sets that are not unexplained or random in the least. Assumptions about what lights or codes must be "obviously unrelated" are among the most common mistakes in new posts here. bisco's suggestion about the inverter coolant pump is a good one. When the power electronics start overheating, you have less driving power available ("mush pedal?"), loss of regen braking capability (brake warning light), and reduction of power to 12 volt systems, which include the steering assist.
Sounds like the brake system, a known problem that may still be covered by a customer support program. However this coverage expires this year on a 2012. While not a likely suspect, your inverter is also covered for another five years. I doubt your hv battery is the cause of a sudden failure but it could be getting old and it has no coverage. Be sure Toyota has your name and proper address so that you can be notified of special coverages. We had a guy yesterday who replaced a failed inverter with a used one at his expense months ago only to have it fail again. Now Toyota won't cover it because it was used. Be cautious if the dealer comes back with a high dollar repair that is not covered.
"Unrelated systems" can sometimes point to the 12 V battery too......and/or the 12 V inverter. Dealerships do NOT replace individual cells.....so why should they test them individually ?
Inverter.................................................... or 12 volt? I don't know of a steering light but there is a traction light that comes on. Looks kinda like 2 z's