Can a front actuator be bad and still work? My light came on when useing 4x4 (although 4x4 still worked). took to the shop and they said the TCM code showed a bad front diff actuator. But they - and myself - verified it seemed to engage and disengage properly. So they cleared the code. LIght is now back on...4x4 still works and disengages. Don't want to waste money on new front actuator if u guys think there is a different problem. What do u think?