Toyota admits its engines are overrated – by its own power testing software

Japan's government slapped it for using the wrong code to produce too-powerful results

Toyota apologized on Wednesday for an incident involving the fraudulent certification of its diesel engines that resulted in a corrective order from Japan's transport ministry.

The local Ministry of Land Infrastructure, Transport and Tourism revealed last week that results of on-site investigation determined test engine control software had been illegally rewritten to calculate engine performance incorrectly.

Prior to the ministry's investigation, Toyota had found irregularities during horsepower output testing. The performance was measured using engine control units (ECUs) running software that differed from that used in mass production. Toyota said using the wrong software meant test results produced "values [that] appear smoother with less variation."

Toyota Motor Corporation stopped shipment of vehicles with affected engines in late January after the problem was identified.

Following the investigation, the ministry confirmed "fraudulent acts" had been committed in five engine models for industrial machinery and three for automobiles. The automaker was ordered to address and rectify the alleged cheating practices.

"It is extremely regrettable that this fraudulent incident could seriously undermine the credibility of the national type designation system and undermine the credibility of Japan's manufacturing industry," the ministry declared in its corrective order.

The ministry gave Toyota a month to fix the error and formulate drastic measures to prevent recurrence. The automaker was also ordered to change its culture so that subordinates felt comfortable reporting issues upward, to strengthen its auditing, and other corrective measures.

The fraud is believed to have occurred for decades.

The affected engines were the 2.8-liter 1GD turbo-diesel four-cylinder, 2.4-liter 2GD turbo-diesel four-cylinder, and 3.3-liter F33A twin-turbo diesel V6. Production of forklifts and industrial machinery was paused, along with work on road vehicles including the Land Cruiser Prado, Bongo Brawny Van, Dutro, Hilux, Innova, and Fortuner models.

On Tuesday, the ministry gave permission for Toyota to lift shipment suspension on three models of automobile engines after verifying a return to compliance.

"Following the announcement of MLITT, Toyota Motor Corporation will resume production and shipment of automobiles equipped with the subject engine models for the domestic market from March 4, 2024," Toyota announced.

"The company will take a step back and make company-wide efforts to prevent the recurrence and ensure compliance with domestic laws and regulations once again," it added. ®

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