LCM will activate emergency lighting if one of the main lights is defective... check all the lights in the rear to see which one is acting up - it could be a corrosive contact, intermittent issue (if the issue presents itself several times in one ignition session, the LCM will stop sending voltage to the offending circuit and activate the bypass)... same applies to the headlights - if the one headlight is out, the fog lights come on automatically, to ensure safe passage...

you replaced the speed sensor - was it bad in the first place? how did you test the bad sensor? did you test the sensor at the plug at the ABS module? i've had an issue with a sensor, not reporting to the plug, when i pulled the sensor from the wheel, the sensor was good... real head scratcher... but.. it was the line, between the sensor and the module - there was a chaffed wire... so, in my case, removing old good sensor and replacing it with a new good sensor would not have yielded any results - the sensor was still good but the line was bad...

also, there was a member, who replaced a sensor with an aftermarket sensor and still had issues, as the voltage read just the half of the value that was present on the other 3 sensors... so, he got himself an OE sensor and the problem went away...

just giving you food for thought...