Motoring journalists from from two different (and competing) outlets in Australia have both reported issues with the off road machines. Each time the problem happened, the engine was switched into a limp home mode, reducing power, and in one instance the vehicle was performing an overtaking manoeuvre at the time.
According to Motoring, a Toyota HiLux went into limp home mode during a comparison test, but in doing so it also switched off various safety systems – one of which was the stability control system.
What causes the problem?
The design of the air intake allows fine particles of dust to get past the air filter, which affects the readings of the mass airflow sensor. The MAF, as it’s known, determines the amount of air coming into the engine so that it can then work out what the correct air to fuel ratio should be.
When these particles hit the MAF, not enough fuel is injected, which causes the mixture to lean out, and the engine’s control unit restricts power, sending into a false limp home mode. And because Australia has dust particles finer than some powders – especially in remote areas – this becomes more than just an inconvenience. It becomes a safety issue.
Australia’s vast distances mean that if the MAF sensor causes the engine to shut down in the middle of the outback, things could become very dire for the stranded driver. But the other issue is when the shut down occurs.
Fairfax media reports it has experienced this issue “in two cars – a Fortuner and Hilux – at times when overtaking at more than 100km/h.”
Toyota says no recall coming
Despite knowing about the issue – which affects more than 170,000 vehicles across the three models – Toyota Australia says that it is not a safety issue and does not necessitate a recall.
“As the vehicle is subject to reduced engine power and can continue to be operated safely, it is not a safety related item that would require a recall,” a Toyota Australia spokesperson told motoring.com.au in a statement. “We have provided details of the experiences in the field in Australia to our head office in Japan and they will be making design changes to improve the performance of the air intake in extremely dusty conditions at the earliest possible opportunity,” a spokesman confirmed.
It’s said that a Toyota service bulletin has already addressed the issue, requiring that the air filter is cleaned more often when the vehicles drive in dusty conditions. This is a standard procedure in most vehicles and you’ll find this information in the owners manual and service schedule. But dealers are being recommended to spend two minutes longer to blow compressed air past the MAF sensor to clean it.
If and when a redesigned intake is made, it will be fitted to existing vehicles at no charge.
Have you come across this issue on your Toyota? We’d love to hear your thoughts in the comments.