FL findlemonlaw.com
Illinois · Article Updated May 23, 2026

Electrical and Software Defects in Illinois Lemon Law Cases

Modern vehicles are largely software. Electrical/software defects drive growing share of Illinois Lemon Law cases when they affect safety equipment or core functionality.

Modern vehicles run on dozens of networked computers. Electrical and software defects affecting safety equipment, drive systems, or core functionality qualify under Illinois’s substantial-impairment test.

What counts as an electrical / software defect

Engine and transmission control software

Bad ECU/TCM software causes stalling, poor shifting, or “limp mode” triggers. Each reflash counts as a repair attempt under § 380/3.

Wiring harness failures

Corroded, chafed, or improperly routed harnesses. Illinois winters can accelerate corrosion.

Battery management system (BMS) failures

Premature 12V battery failures, “vehicle drained” no-start conditions.

Safety-equipment software bugs

When software defects affect ABS, traction control, stability control, lane-keep assist — strong ICFA exposure.

ADAS failures

Adaptive cruise, lane departure warning, automated parking — when these fail unpredictably, safety hazards.

Infotainment crossing into safety

When failures spill into safety equipment — backup camera, climate, ADAS warnings.

Software reflashes as repair attempts

Each reflash counts as a repair attempt. Four reflashes meets the four-attempt threshold.

OTA updates

Tesla and others use OTA updates. Trends toward “yes” when the OTA targets a specific defect.

Diagnostic challenges

  • Record video.
  • Note specific trigger conditions.
  • Multi-day diagnostic holds.
  • Get OBD-II scan data.

TSBs and ICFA willfulness

When a TSB exists and the manufacturer refused refund, ICFA “knowing” violation findings produce treble damages.

What you should do

  1. Document each repair attempt — dealer visits AND OTA updates.
  2. Note specific trigger conditions.
  3. Save dash-cam or smartphone video.
  4. Send § 380/3 notice.
  5. Get a free case review.

Related

Think you've got a lemon?

Compare your situation to your state's requirements — and connect with a vetted lemon-law attorney for a free case review.