Panasonic Shows U-26PE1U6 Technical Data & Service Manual page 176

(5) [Alarms "F04," "F06," "F07," "F08," "F12"]
CN020, 021, 022, 023,
and 024 (TD, TO, C1, C2, and
TS sensors) connected
correctly to the outdoor unit
C2, and TS sensor resistance*
Check the outdoor unit
Replace if PCB has failed.
4
Are connectors
control PCB?
Yes
Are the TD, TO, C1,
characteristics OK?
* Refer to "4-4. Table of Thermistor Characteristics."
Yes
control PCB.
Sensor trouble
No
No
4-12
4. Service procedures
Correct the connector
connections.
Replace the TD, TO, C1,
C2, or TS sensor.