2016 Toyota Prius problems

Filed Oct 30, 2026 · Engine · IN

The front exhaust pipe assembly (heat exchanger) on my 2016 Toyota Prius leaked engine coolant internally into the exhaust system. Toyota has documented this condition in Technical Service Bulletin T-SB-0135-19 ("Low Coolant, MIL ON DTC P148F00, and/or Poor Heater Performance") for 2016-2019 Prius vehicles and released a redesigned replacement part (17410-37D40). In [October 2026], at about [97,000] miles, I found the engine coolant reservoir was emptying about every night (nearly a full reservoir) with no external leak. A shop pressure test found no leak. Coolant collected inside the tailpipe after the car sat overnight, and white steam came intermittently from the exhaust while driving. The car stored code P148F00. On XXX a Toyota dealer ([DEALER NAME], [XXX]) confirmed coolant leaking from the front exhaust pipe heat exchanger, per T-SB-0135-19, repair order #[RO NUMBER], and quoted $1,870 to replace the front exhaust pipe with the updated part. My concern is that a vehicle losing coolant this fast can run low without warning and overheat while driving, which can cause engine damage or loss of power, and the white steam from the exhaust may reduce visibility for drivers behind. I also worry that coolant entering the exhaust damages the catalytic converter. The car has been serviced regularly, and the leak was not caused by an accident or impact. Toyota covered this repair under its emissions warranty for 8 years/80,000 miles, but my car is past that and Toyota has declined goodwill coverage (Toyota case #XXX). I'm reporting this so the federal safety agency can see that the failure is happening in vehicles outside that warranty period and can evaluate whether it is a safety defect. Vehicle: 2016 Toyota Prius, VIN [XXX] Component: Engine and engine cooling / exhaust system Crash: No. Fire: No. Injuries: No. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Oct 6, 2026 · Acceleration, Fuel system · CA

I turned on my car in a flat parking lot, reversed out of my spot, and drove up to a traffic light to exit the parking lot. When the light turned green, I took my foot off the brake and tried to accelerate, but nothing happened. After a few seconds, my car lurched forward with a sudden jerk, and I was able to exit, but this behavior (no movement, then sudden jerk) continued to happen. I was scared that I would get into an accident, so I pulled over and turned the car off and on. The behavior continued. I drove to a safe location, and parked the car. I noticed the engine kept revving up and down, even though I was parked, and the hybrid battery indicator showed no charge. I turned off the car, and had dinner for about an hour. After I finished dinner, I started the car, and it was driving normally again (creeping forward as soon as I took my foot off the brake), but I was afraid the problem would happen again, at a dangerous moment. There were no warning lights or messages while this problem was happening. I explicitly checked that the parking brake was not set.

Filed Jun 29, 2026 · Brakes, Driver assistance · 100,028 miles · CA

The contact owns a 2016 Toyota Prius. The contact stated that while the vehicle was on and running, the ABS and traction control warning lights illuminated, and the messages "Braking Power Low - Stop in a Safe Place”, “See Owner's Manual", "Braking Power Low - Visit the Dealer", and "ABS Malfunction - See Dealer" were displayed. The contact stated that while driving approximately 35 MPH and depressing the brake pedal, the brake pedal was firm. The vehicle was taken to a dealer, and DTC: C14B6 was retrieved, indicating that the brake booster needed to be replaced. The vehicle was not repaired; however, the code was cleared. The vehicle was then taken to an independent mechanic, where the information from the dealer was relayed that the brake booster needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure. The failure mileage was approximately 100,028.

Filed May 12, 2026 · Brakes · FL

Second time !!!! during ownership of car that brakes fail. Same problem as before Brake Actuator/Booster Failures: Multiple reports indicate issues with the ABS actuator or brake booster pump, leading to warning lights ("Braking power low", "ABS system malfunction").

Filed Apr 21, 2026 · Fuel system · AZ

The car has a very strong gas smell, especially when full.

Filed Aug 4, 2025 · Fuel system · GA

Found coolant leak from heat exchanger into exhaust pipe. Looks like, T-SB-0135-19.

Filed Apr 11, 2025 · Lights · AZ

The headlights are either too bright or aimed poorly that it blinds oncoming traffic, who frequently flash their high beams at me. This occurs without any load in back and without me using the high beams. Can Toyota either adjust the bulbs or place a film on the headlights to prevent blinding oncoming traffic? Thank you!

Filed Mar 13, 2025 · Engine · GA

Water pump failed without warning and caused irreparable damage to the engine ("blown" engine requiring replacement). Vehicle began to stall and not respond to attempted acceleration while traveling on 4 lane divided highway, 55 mph speed limit. One "Maintenance Required" message was received the previous week, but disappeared. This is the same message that appears for routine oil changes. No other warning messages were noted at the time of the incident, no unusual noises, and no smoke or other sign of overheating. Driver was able to steer vehicle to safety, but this failure could result in stranding on a busy, dangerous interstate highway. For such a critical piece of the vehicle (i.e., the water pump), there should be obvious warning message(s) and dedicated monitoring of the equipment.

Filed Jan 25, 2025 · Engine · CA

Refer to TSB 0135-19 dealer denied repairing under the California emissions defect and performance warranty.

Filed Jan 16, 2025 · Engine, Steering · PA

My car suddenly stopped in the middle of the road with message "Hybrid system stopped steering power low". Safety concern to this happen on the middle of road during rain or cold.