How Software Is Eating the Car

Robert N. Charette, How Software Is Eating the Car, IEEE Spectrum, 07 Jun 2021.

Ten years ago, only premium cars contained 100 microprocessor-based electronic control units (ECUs) networked throughout the body of a car, executing 100 million lines of code or more. Today, high-end cars like the BMW 7-series with advanced technology like advanced driver-assist systems (ADAS) may contain 150 ECUs or more, while pick-up trucks like Ford’s F-150 top 150 million lines of code. Even low-end vehicles are quickly approaching 100 ECUs and 100 million of lines of code as more features that were once considered luxury options, such as adaptive cruise control and automatic emergency braking, are becoming standard....

According to the 2020 Automotive Defect and Recall Report compiled by financial advisory firm Stout Risius Ross, 2019 was a record-setting year with 15 million vehicles recalled for electronic component defects. Half of the recalls involved software-based defects, the highest proportion Stout has measured since 2009.  

Nearly 30% of the defects were related to software integration where a failure results from software interfacing with other electronic components or systems in a vehicle. Mitsubishi Motors recalled 60,000 SUVs because a software error in their hydraulic unit ECU interfered with multiple safety systems. 

Finally, more than 50% of the defects featured a failure that was not clearly caused by a software defect, but an update to the software was the remedy used. 

Ford Motor Company recalled certain models of its Fusion and Escape vehicles because coolant could enter their engine cylinder bores, which could permanently damage their engines. Ford’s fix was to reprogram the vehicles’ power-train control software to reduce the likelihood of coolant entering the engine cylinders. Stout’s data shows that occurrences of software being used to fix vehicle hardware problems has steadily increased in the past five years. ...

EV + AI = Unmanageable Complexity 

The functionality and complexity of the decentralized ECU architectures used in ICE vehicles “have reached their limits,” Tamara Snow, head of research and advanced engineering for Tier 1 auto supplier Continental AG is quoted in Wards Auto as saying. This is especially true if full autonomous driving capabilities require anywhere near the estimated 500 million or more lines of code.