[neeldub]

Finally I have been able to resolve this issue. One of the wires was crushed under a screw which secures the lower cover of the door mirror to the body which is metal thus causing a grounding issue which prevented the mirror from heating up. A quick fix was to cut the wires, solder and apply a heat shrink so cover the repair.

All error codes have now cleared and heating functions is working as it should.

I suggest you completely strip down the mirror and examine the wiring from both ends of the mirror harness.