DTC B10A6-64: Light Switch Error Signal Received (BCM): Notes

WARNING: This page is about a different car, the 2020 Mazda MX-5 Miata. However, it is still accessible from the selected car via links, so may be relevant.

DTC B10A6:64 (BCM) DETECTION CONDITION AND POSSIBLE CAUSE

Description	Light switch error signal received
Detection condition	BCM receives error signals from the start stop unit for 5 s or more with the ignition switched ON (engine off or on).
Fail-safe	Exterior lighting system Turn the TNS (parking lights) and headlights LO on, and turn off other exterior light controls.
Possible cause	Start stop unit malfunction Light switch malfunction BCM malfunction
System wiring diagram	Not applicable