Fiat 500e Electric Car Recalled Again Due to New Software Fault, Caused by Bad Math

Following on from recall earlier this spring in which it had to recall 5,600 Fiat 500e electric cars to remedy a software issue with the car’s electric vehicle control unit, Fiat Chrysler has issued another recall to fix yet more faulty programming in the same component.

As GreenCarReports detailed on Friday the recall is believed to affect some 3,851 Fiat 500e hatchbacks manufactured between March 8, 2013 and March 7, 2015, and can cause affected cars to suddenly shift into neutral while driving.

According to documents filed by Fiat Chrysler with the National Highway Traffic Safety Administration, the fault can occur in affected vehicles when the cruise control is active and the driver tries to rapidly change the set speed.

The Fiat 500e has been recalled yet again.

The Fiat 500e has been recalled yet again.

In Fiat Chrysler’s own words, “Rapid operations of the cruise control speed adjustment switch or accelerator tip/in pedal applications while in cruise control may set a diagnostic trouble code in the Electric vehicle Control Unit (EVCU) that can result in a shift to natural condition.”

The root cause? Incorrect settings — and bad math — between various in-car computer systems.

In its full explanation as to the cause, Fiat Chrysler says that ‘due to software updates,’ the internal vehicle speed monitoring system was incorrectly changed from miles per hour to kilometres per hour. Meanwhile, the System Torque Monitoring Ring (STMR) — another essential component to modern vehicles which helps figure out how much torque is being sent to the wheels by the motor — was still set to miles per hour.

“This created a math error and subsequent trouble fault code error state due to implausible torque readings,” the automaker said.

The root cause? Incorrect settings — and bad math — between various in-car computer systems.

Worryingly, the fault condition can only be reset by power-cycling the car — otherwise known as turning it off and then on again — and Fiat Chrysler says the fault is not detectible by the driver until the fault is set and the vehicle shifts into neutral.

With the fault and its root cause correctly identified, Fiat Chrysler says it will begin the official recall on or around July 5, with owners of affected cars due to be contacted in the next few weeks to arrange the necessary service appointment at which the units will be reprogrammed free of charge.

In the meantime, Fiat 500e customers can call Fiat Chrysler’s customer service centre on 1-(800) 853-1403, quoting recall number R20. Additional information on the recall can be found via NHTSA’s website.

Although the Fiat 500e has received rave reviews from those who have driven it and has enjoyed something of a renaissance in buyer interest of late thanks to unbelievably good lease deals in some parts of California, it is very much considered a compliance car both by the automotive industry at large and Fiat Chrysler itself.

Owners of affected cars will be contacted in due course, with recalls due from July 5.

Owners of affected cars will be contacted in due course, with recalls due from July 5.

Built exclusively to satisfy California’s Zero Emission Mandates requiring large-volume automakers to produce a certain number of zero emission vehicle in order to sell in the state, it is currently only available to buy in California and Oregon.

Despite only being in production since 2013, this is the fourth major recall to affect the Fiat 500e. Back in August 2013, Fiat Chrysler was forced to recall early Fiat 500e models to remedy a problem with the vehicle’s half-shafts. Then last summer, Fiat recalled the Fiat 500e again to remedy a problem with the Power Inverter Module which resulted in liquid coolant leaking onto the vehicle’s sensitive power electronics, ultimately causing a short circuit and an incapacitated vehicle.

The third recall, as we noted at the top of this article, took place earlier this year to fix faulty coding with the electric vehicle control unit that could cause the vehicle to enter into ‘limp home mode’.

Do you have a Fiat 500e? How would you rate your ownership experience thus far? Have the spate of recent recalls caused you to worry about build quality, or has your local Fiat Chrysler dealer dealt with them in a courteous and professional manner?

Leave your thoughts and ownership experiences in the Comments below.


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