A communication error (COMS error) may occur due to a faulty resistor on the IPM (Intelligent Power Module) board.
To confirm the fault:

  1. Set the multimeter to diode test mode.

  2. Measure across the suspect resistor:

    • In one direction, the reading should be approximately 0.45 V (diode forward voltage).

    • When reversing the meter leads, the reading should be approximately 1.1 V.

  3. Diagnosis:

    • If the meter displays O/L (open loop) or open circuit in both directions, the resistor is faulty and must be replaced.