Been having a intermittent service 4wd issue since last winter. Sometimes it will go into 4wd fine and other times it won’t. I just replaced the front diff actuator and encoder motor. Well I’m still having the issue so we read the codes with a solus last night and getting c0379 for the front diff not engaging. I just changed the diff fluid today, it was a chocolate milk brown looking and didn’t have much metal shavings on the plug. About the same as last time I changed it. Also sometimes when it says it’s in 4 hi it’s really only in 2wd and sometimes it goes into 4 hi just fine. Other times it won’t even go and just says service 4wd system. Any ideas?