Configuration/Communication Diagnostic Codes - 39 (Idf Comm Error) - Friedrich VRP12K Service And Parts Manual

Configuration/Communication Diagnostic Codes – 39 (IDF Comm Error)
IDF Layout:
When checking communication, use the ground (blk) to
reference all other pins in VDC:
3‑pin block – Power
Red – L1
Grn – Ground
Blue – L2
4‑Pin block – Communication
Brn – 10V
Yel – Signal to Fan (T) ~1‑5VDC
Blk – Ground
Blu–Tacfrom Fan (F) ~1‑5VDC
Verify proper voltage to fan on power block, then make
sure 10v is present on comm. block. Start a call for fan
and measure signal to fan. If voltage is present, FMC is
good. Check fan for blockage or possible demag.
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