In the front of the RAV4 there is an ECU that controls the lights (the high and low beam headlights and the turn indicators). In most cars there is such an ECU because the days of there being a simple switch to turn on lights are long gone: lights are smart, and include things like motors to level the headlights (so when the car is loaded with heavy luggage, the lights are turned to compensate), steering headlights to illuminate the corners, to automatically detect if the lights have failed, to turn on pumps to spray water on the lights, and so on. And on the RAV4, it’s to also choose which LEDs in a grid are lit up to not dazzle oncoming drivers but still light the rest of the road.

The DTCs showed that communication with the lighting control ECU was lost. This isn’t surprising since the thieves had ripped the cables out of it. But the DTCs also showed that lots of systems had failed: the control of the front cameras, the hybrid engine control system, and so on. How could that be? This was the next clue: the ECUs probably hadn’t failed, but rather the communication to them had been lost, and the diagnostics had flagged this as a fault. The common factor: CAN bus.