85
13 - TROUBLE SHOOTING
Troubleshooting Chart 9
Is HRU terminal being used
on the auxiliary SCU board
(see section 8) ?
NO
YES
Fix Wiring
Connection
Fix Wiring
Connection
E40
- HRU/URC Unit test error
Is wiring connection to HRU
terminal secure?
NO
YES
Is wiring connection from
SCU board to main board
secure?
NO
YES
Is Parameter P42 set
to 1?
NO
YES
Is P42 parameter set
to 0?
NO
YES
Done
Set P42 to 0
NOT OK
OK
Replace SCU board
NOT OK
OK
Replace Main
Control Board
Done
Set P42 to 1
Not OK
OK
Done
Is HRU accessory
operating properly?
NO
YES
Correct HRU
Accessory
P/N 240011654, Rev. C [06/08/2017]