Service Guide

21
Defrost Diagnosis:
1a) Time-Initiation: 2-hr. defrost timer terminates.
(1) CM Diagnosis: Conrm defrost icon turns on, "dEF" is displayed, and Comp and
EvapFM icons turn off. If not, replaceCM.
(2) Comp and ConFM Diagnosis: Conrm Comp and ConFM de-energize.
If not, check for 115VAC at CM C1 (V) to neutral (W). If 115VAC is present,
replace CM. If 115VAC is not present and Comp and ConFM continue, check
CR#6(R) to neutral (W). If 115VAC is present, replace CR.
(3) EvapFM Diagnosis: Conrm EvapFM de-energizes. If not, check for 115VAC at
CM F5 (W/BU) to neutral (W). If 115VAC is present, replace CM.
1b) Manual-Initiation: After pressing the manual defrost button, check the following:
(1) CM Diagnosis: Conrm Comp and EvapFM icons turn off, defrost icon turns on,
and "dEF" is displayed. If not, replace CM.
(2) Comp and ConFM Diagnosis: Conrm Comp and ConFM de-energize.
If not, check for 115VAC at CM C1 (V) to neutral (W). If 115VAC is present,
replace CM. If 115VAC is not present and Comp and ConFM continue, check
CR#6(R) to neutral (W). If 115VAC is present, replace CR.
(3) EvapFM Diagnosis: Conrm EvapFM de-energizes. If not, check for 115VAC at
CM F5 (W/BU) to neutral (W). If 115VAC is present, replace CM.
2) Defrost Temperature Termination: DTh warms to 44°F (6.6°C)? If not, conrm DTh
status. See "II.D. Thermistor Check." If DTh is in proper range, have Comp, ConFM,
and EvapFM energized? If not, see "7a) EvapFM Diagnosis" or
"7d) Comp and ConFM Diagnosis"above.
Legend: CL–cabinet light; CLS–cabinet light switch (FGE); CM–control module;
Comp–compressor; ConFM–condenser fan motor; CR–compressor relay;
CTh–cabinet thermistor; DCD–direct current driver; DS–door switch (FS/HS);
DSR–door switch relay (FS/HS); DTh–defrost thermistor; EvapFM–evaporator fan
motors; HPS–high-pressure switch; TXV–thermostatic expansion valve