Toyota Recall Woes Deepen

As if the unintended acceleration “crisis” (Toyota’s word, not ours) wasn’t bad enough, Toyota’s Prius has come under fire for an issue with its regenerative braking system.

During braking, the Prius relies on two braking systems to bring the hybrid to a standstill. The first, its regenerative system, basically kicks the electric motor into reverse. This causes it to generate electricity, which is then piped into the battery pack. Of course, this system doesn’t provide the same linear resistance as friction brakes, so it requires a software model that causes the system to mimic standard braking. It also doesn’t supplant standard brakes, which are used at extremely slow speeds to actually stop and hold the car in place, as well as during emergency braking.

Apparently, the Prius’ braking problem stems from some irregularities in the transition between regenerative and friction braking systems on less than ideal road surfaces. Causing a short period of unresponsiveness, it affects all Priuses sold before the end of January.

Understandably, Toyota had been ordered to begin an investigation into the problem when the U.S. Transportation Department began an investigation of their own after learning that Toyota was already aware of the issue. Prius owners can expect a recall shortly.