Mitsubishi E6 fault code

[grovecoooling]

Can anyone advise me on an E6 error code i have on a Mitsubishi electric Mr slim wall mount unit.

The E6 fault in the tech book is a communication error between indoor and outdoor unit, the unit has been running fine for just over a year.
I have checked the voltage coming out of the outdoor pcb and i have 240v across S1+S2 terminals and S1 to earth, this is also ok at the indoor unit. I was advised by Mitsi tech to check S1,S2, I have 18-22dc voltage between S2 and S3 at condenser and this is the same at indoor unit, i have not spoke to them again, and wondered if anyone has had a similar fault and could advise, im pressuming it requires either an indoor or outdoor Pcb.

Please help

[Airconking]

As you have already said, sounds like a pcb. Phone Mitsi back and they will go through the required checks to determine which 1.

[Improver]

I think its the outdoor p.c.b that is defective as you have your signal voltage from indoor to outdoor which i think should be 24vdc your not far off with 18-22 vdc. I agree with airconking to phone mitsi tech they are quite helpful and talk you through what checks you need to do to i.d fault.