Some RAV4 Primes could lose power in EV mode and extreme cold
Fix is a software update, done at the dealer
Toyota is recalling the RAV4 Prime over a possible sudden loss of power. 4,545 copies of the 2021 Toyota RAV4 Prime PHEV in Canada are being brought back over the issue, which will be fixed with an engine control software update.
The recall was updated today by Transport Canada on the Motor Vehicle Safety Recalls Database. According to Transport Canada, “on certain RAV4 Prime models, rapid acceleration could cause the battery voltage to drop suddenly while driving in “EV mode” in cold temperatures. If this happens, the hybrid system could shut down and cause a sudden loss of power to the wheels.”
Toyota is also recalling just over 16,000 RAV4 Prime models in the U.S. To go with it, they’ve filed documents with U.S. safety regulator the NHTSA that explain more about the problem.
“The subject plug-in hybrid vehicles contain software in the Hybrid Vehicle Control ECU (HEV ECU) to calculate the Hybrid battery (HV battery) output limits (maximum operating output) by monitoring battery voltage, state of charge (SOC), electrical load, and other parameters for battery protection. Due to certain characteristics of the software logic, the HV battery output may not be limited as required to protect the battery. If the accelerator pedal is rapidly pressed to further accelerate the vehicle after it has been continuously driven in “EV mode” in cold temperature and the HV battery voltage decreases, the voltage may drop rapidly below a specified threshold. If this occurs, the vehicle will display a warning message and the hybrid system will shut down, resulting in loss of motive power. If the vehicle loses motive power while being driven at higher speeds, there could be an increased risk of a crash,” Toyota says in the document.
In short, the high-voltage battery might not have enough voltage for EV mode when the temperature is very cold and the battery is low. The cold weather could mean the computer doesn’t know, and so doesn’t turn on the gas engine. That means you stop.
Toyota received reports from users about the issue as far back as March of 2022, but it took time to investigate and isolate the issue. Toyota says it has received no field reports of the issue in the U.S. and just five warranty claims. The same data wasn’t given for Canada.
The fix is a software update. Toyota will let its owners know about the recall by mail and will include instructions to make an appointment with a dealer for the software fix.
