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Mitsubishi · Heat pump

E6 Indoor/outdoor communication - indoor not receiving

High severity Mr. Slim PEAD-RP JA(L) ducted indoor unit

What the control is telling you

The indoor board has not received a valid signal from the outdoor unit for 6 minutes after power-up, or for 3 minutes during operation. On twin/triple systems, also set when the indoor board does not get the outdoor board's permission-to-send signal for 3 minutes.

Applies to: PEAD-RP35/50/60/71/100/125/140JA and JA(L) ducted indoor units (220-240 V models)

Likely causes

  • S1/S2/S3 indoor-outdoor wire loose, shorted or crossed
  • Faulty send/receive circuit on the indoor board
  • Faulty send/receive circuit on the outdoor board
  • Electrical noise on the indoor/outdoor wire

Test and repair steps

  1. Turn the unit off at the remote first, then switch off the breaker before opening the unit or unplugging connectors.
  2. Check the S1, S2 and S3 connections at both terminal blocks for looseness, damage or reversed wires. On twin/triple systems, check every unit.
  3. If you have the A-Control service tool (PAC-SK52ST), read the LED code on the outdoor board; if it shows EA-EC, follow that code first.
  4. Cycle power. If the code returns, replace the indoor or outdoor control board.
  5. On twin/triple systems another indoor board may be the faulty one.

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Source: Mitsubishi Electric PEAD-RP35-140JA(L) Service Manual, 10-3 Self-diagnosis action table, p.34. Summarized in our own words; check the original manual for your model.

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