Toyota is issuing a series of recall notices around the world to have a problematic component replaced in the power supply circuit of some 110,000 hybrid cars. If not addressed, the fault could lead to the company’s hybrid cars suddenly losing power.
This is the latest in a long line of recalls that have hit the world’s number-one automaker in recent years. Once famed for the solid engineering and build quality of its vehicles, Toyota appears to have struggled in the last decade or so, as some of its most popular models have been recalled to have problems addressed.
The latest safety alert concerns the company’s hybrid Highlander SUV, as well as the Lexus RX400h. Vehicles sold around the world are at risk.
The problem concerns a component that, if it fails, can blow a fuse in the vehicle’s electrical system, bringing the car to a sudden halt. In the last 18 months, the company has already had to recall some 12 million vehicles to have a range of problems checked and, where necessary, repaired.
The most recent recall notice from Toyota concerning hybrid vehicles is voluntary and covers the 2006 and 2007 model years. The recall was announced on 29 June by Toyota Motor Sales in the USA.
About 45,500 of Toyota’s Hybrid Highlander models and another 36,700 Lexus RX400h SUVs sold in the USA are subject to the recall. This particular notice does not apply to any other Toyota models in the US market.
The vehicle’s Intelligent Power Module, or IPM, contains a control board on which some soldering of transistors failed to meet the necessary standards. If the vehicles are subject to high-load driving, heavy current flows through the IPM, which is inside the Hybrid System Inverter, could generate enough heat to damage the soldered connections.
If the soldered joints fail, the most likely outcome is that the vehicle enters a fail-safe driving mode. Occupants will likely see a variety of warning lamps lighting up before the vehicle’s power fails.
In most cases, the vehicles will still be capable of running for a short distance after the failure. In some cases, however, the failure of a transistor could trigger a fuse in the power supply circuit to blow, cutting all power to the vehicle.
Toyota says it is still working on acquiring the replacement parts needed to affect a repair. As the components are obtained, the company will be contacting the owners of vehicles subject to the recall.
Between now and the middle of July, owners of these vehicles can expect to receive notification from Toyota via first-class post. Toyota says it will issue owners with a second notice once it has enough of the replacement parts it needs.
When owners take their vehicles to authorised Toyota dealers, engineers will inspect the IPM to see if it needs to be replaced. Toyota says there will be no charge for the replacement.
Hopefully, Toyota’s rapid work on dealing with the latest problem will help to erase memories of the way it fumbled the ball earlier, when it was accused of trying to cover up problems, even after safety regulators had become aware of allegations of an issue.