E4

Remote Controller Transmit Error (Remote Controller Side)

Mitsubishi Electric · PAR-21MAA MA Remote Controller

What does E4 mean?

The remote controller has detected an error in transmitting signals to the indoor unit or other system components. This indicates a problem with the remote controller's transmission circuit or its communication line, preventing it from sending control commands or status requests.

Common Causes

  • Remote controller fails to transmit signals to the indoor unit.
  • Faulty remote controller internal circuitry or communication module.
  • Power supply issue to the remote controller.
  • Obstruction or damage to the remote controller's transmitter.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Verify the remote controller model is an MA remote controller (PAR-21MAA) as specified.

  2. 2

    Inspect the transmission wire connected to the remote controller for signs of electrical noise interference.

  3. 3

    Cycle power to the unit (turn off, then on again) to re-check for the error.

Browse all codes in this manual (26)
Verified technical data. Last updated: March 2026

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Source: Mitsubishi Electric PAR-21MAA MA Remote Controller