Fault on mitso split system

[Simeonx1]

6month old unit
The air con is coming up with a Fault flashing 7 times.
In the manual it says Problems could be .

Refrigerant is insufficient. = Refrigerant is leaking

Heat exchanger sensor 1 error = Broken heat exchanger sensor 1 wire, poor connector connection .

It doesnt seem to have a leak because i checked outdoor flares with bubbles. and has suction pressure at 850kpa with near 40c ambient .

i was there for 2 hours and turned unit of and on 5 times. couldnt see fault but customer has rung up again and said its doing same thing.

Would moisture in the system make this fault come up . but then the suction would be lower.

Could it be faulty inner connection wires ?

What heat exchanger should i look for sensor . out door or indoor ?

[stufus]

Evap coil sensor.
Cheers
Stu

[jimmyjewfish]

indoor sensor could be faulty like stufus said cause that how it senses if there is a gas shortage if the gas is fine then the sensor is faulty giving wrong reading