09/06/2026
This 2022 Toyota Yaris came in with a whole range of warning lights after being repaired as a repairable write-off. A number of components had been replaced, including the dashboard, airbag module, radar/camera system, and front bar.
Initial diagnosis showed communication faults for the yaw rate sensor and steering angle sensor. At first, the fault wasn’t obvious, as all modules were communicating normally with the scan tool.
Commonly, newer Toyotas require replacement modules to be registered online through Techstream using an ECU security key. After doing this, the yaw sensor faults went away, which made sense as it is integrated into the airbag module which was replaced.
The steering angle sensor fault is linked to these same symptoms, but this one turned out to be a separate issue. We could communicate with the steering angle sensor, and live data showed correct steering values, but the information wasn’t being transmitted to the rest of the vehicle. What gives?
Using Techstream’s CAN communication analysis and wiring diagrams, we traced the fault to a blown ignition fuse supplying the steering angle sensor. Two separate fuses power the steering angle sensor, permanent live and ignition.
After replacing the fuse, carrying out security synchronization, and completing a full ABS calibration/learn procedure, all warning lights and history (RoB) fault codes were cleared, and the vehicle was back to normal.
A repair like this would not have been possible without dealer-level tooling - something Toyotas don’t often require, but increasingly do on newer models.