DISK REDUNDANCY FAILED due to faulty chassis

• ONTAP 9
• DS212C

• AutoSupport trigger subject HA Group Notification (DISK REDUNDANCY FAILED) ERROR.
• SYSCONFIG-A shows less shelves over 1 path:

Path using IOM B:

Shelf 0: DS212-12 Firmware rev. IOM12G A: 0100 IOM12G B: 0100
Shelf 1: DS212-12 Firmware rev. IOM12B A: 0130 IOM12B B: 0130
Shelf 2: DS212-12 Firmware rev. IOM12B A: 0130 IOM12B B: 0130
Shelf 3: DS212-12 Firmware rev. IOM12B A: 0130 IOM12B B: 0130
Shelf 4: DS212-12 Firmware rev. IOM12B A: 0130 IOM12B B: 0130
Shelf 5: DS212-12 Firmware rev. IOM12B A: 0130 IOM12B B: 0130
Shelf 6: DS212-12 Firmware rev. IOM12B A: 0130 IOM12B B: 0130

Path using IOM A:

Shelf 0: DS212-12  Firmware rev. IOM12G A: 0100  IOM12G B: 0100
Shelf 5: DS212-12  Firmware rev. IOM12B A: 0130  IOM12B B: 0130
Shelf 6: DS212-12  Firmware rev. IOM12B A: 0130  IOM12B B: 0130

• STORAGE-SHELF.XML shows chassis sensor error.

Shelf Name:1.4
Shelf component with error:1,10
Sensor Location:
1->front of the shelf on the left, on the OPS panel
11->rear of the shelf at the top left, on shelf module A
Error Text:
Critical error detected in module "1".
Temperature reported by temperature sensor "10" exceeds the specifications for the disk shelf or its components.

• Replacement of shelf 4 IOM  A doesn't resolve the issue.