From Ross-Tech Wiki
03841 - RPM Sensor Rear Left: Incorrect Signal
- Incorrect ABS coding when both left and right WSS (Wheel Speed Sensors) have Incorrect Signal DTCs such as 03841 and 03842.
- Incorrect rear WSS (Wheel Speed Sensor)
- Check ABS coding when both left and right WSS have Incorrect Signal DTCs
- Check Installed WSS part numbers
- Part numbers can be verified based on PR-Codes and parts catalogs such as PartsLink24. Both are explained on this page: Production Codes (PR-Codes) can be found on the Vehicle Data Label