Report: Subaru BRZ, Scion FR-S facing rough idle and stalling situations

Subaru and Toyota are facing some glitches with their new rear-wheel-drive sports car – the BRZ and the GT 86 (Scion FR-S). According to reports, owners have been complaining about rough idle and stalling conditions.

[slider id=107480]
[slider id=107830]

Toyota says that the issue is being caused by a software mapping glitch. Officials say that the cause of the problem is a simple software bug and that there is no mechanical issues with teh car.

Some owners have disagreed with the two companies explanations, saying the suggested fix hasn’t kept the problem from recurring.

According to Toyota spokesman Brian Lyons when the ECU is installed, it adapts to the car’s powertrain and owner’s driving patterns, a process known as adaptive learning. Within 100 miles, those settings are basically frozen in the ECU. Basically what happens next is that the ECU starts monitoring driving conditions and when the engine is found to be out of tolerance, the software fires back a fault code – that in turn fires off a rough idle or stalling situation ensues.

Toyota says that to fix the issue, a technician will reflash the ECU to correct the problem if the car has less than 100 miles. If the car has more than 100 miles, the technician would replace the ECU.

“It does involve the variable valve timing, but it does not involve a mechanical repair,” Lyons said. He said the rough idle is the result of the ECU’s attempting to work around its detection of the anomaly, rather than what is triggering the fault code. The reflash “broadens the tolerance of detection.”

Separately, while Subaru agrees that ECU mapping is the cause, it believes the ECU reflash is the only needed repair.

“This is not a mileage-dependent condition. No replacement of the ECU is needed at any mileage to rectify the issue. The ECU re-flash is the fix. There is not a defect concerning the ECU,” said Subaru spokesman Dominick Infante.

– By: Omar Rana

Source: AutoNews