The recall affects 30,790 UK-registered Prius cars. Worldwide, there have been no reports of any accidents or injuries relating to this issue. In Europe Toyota has recorded 11 field reports of the issue occurring.
Toyota has identified through its stringent quality reporting programme that there may be an issue concerning the software used to control the boost converter in the Intelligent Power Module, part of the hybrid system’s inverter assembly. The boost converter is required when driving with a high system load, for example when accelerating hard from standstill.
Toyota has identified that the software setting could lead to higher thermal stress occurring in certain insulated-gate bipolar transistors in the boost converter which may lead to them deforming or being damaged.
Should this happen, warning lights may be illuminated and the car is likely to switch to “failsafe” operation – it can still be driven, but with reduced power. In limited cases the hybrid system may shut down, causing the vehicle to stop. The driver will not experience any change in the vehicle’s behaviour or performance prior to the problem occurring.
Toyota can confirm that this issue will not occur in other Toyota hybrid vehicles, as these use different transistor structures and control logic.
All the vehicles affected by this issue are being recalled so that the control software can be updated.
Vehicle owners will be contacted by Toyota within the coming weeks by post or telephone and asked to make an appointment to bring their car to their nearest Toyota centre, in accordance with Vehicle and Operator Services Agency (VOSA) guidelines.
The software update will take about 40 minutes to complete; the work will be carried out free of charge.
Customers can check whether their vehicle is affected using a registration look-up function in the owners section of the main Toyota website (www.toyota.co.uk).
If owners require additional information they can contact Toyota Recall Helpline on 0800 1388744.