The system uses solenoid valves and vacuum to activate the 4WD and quite often these solenoids fails causing the system to malfunction with the dash indicators blinking to warn you of it.
The present problem of the lights blinking suddenly could be due to a fault with one of the solenoids leaking, allowing vacuum to pass through instead of keeping vacuum out. This would result in the 4WD trying to engage while vehicle is moving and thus the grinding the noise.
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Saturday, January 4th, 2014 AT 10:43 AM