898150-UIM-B-0113
Johnson Controls Unitary Products
29
OUTDOOR UNIT LED STAUS CODES
P8
Intelligent Power Module
temperature is too high
All system functions are terminated except
indoor fan.
Intelligent Power Module high temperature
error can result from any of the following:
• Loss of cooling to the heat sink
• Low voltage
• High ambient temperature
• Loose screws fastening the outdoor con-
trol to the heat sink Check all and correct,
if necessary.
U1
Compressor current test
circuit malfunction
All system functions are terminated except
indoor fan.
Replace outdoor control.
U2
Compressor protection
against loss-of-phase
Unit will cycle off.
De-energize system and restart.
U3
Unstable DC voltage protection
All system functions are terminated except
indoor fan.
Input voltage is not stable.
U4
Compressor reverse protection
Unit will cycle off.
De-energize system and restart.
U5
Entire unit current
monitoring malfunction
All system functions are terminated except
indoor fan.
Outdoor control has malfunction. Replace
control.
U7
Reversing valve malfunction
All system functions are terminated.
• Check input voltage on outdoor unit ter-
minal strip (N and L terminals). If lower
than 175 VAC, correct voltage problem.
• Check reversing valve wiring connection
for damage.
• If voltage and wiring connections are cor-
rect, replace reversing valve.
U8
Disconnection of the
exhaust temperature sensor
Unit will cycle off.
• Check for proper wiring connections and
loose wires at outdoor control (CT1, 2)
input plug
• Check for continuity across overload pro-
tection sensor terminals mounted at top of
compressor.
U9
Outdoor unit zero cross detection error
All system functions are terminated except
indoor fan.
Replace outdoor control.
TABLE 12:
Error Codes
Indoor Character
Display
System Status
Troubleshooting for
Possible Causes
TABLE 13:
Led Status Codes
NO Malfunction
description
LED1 LED2 LED3 LED4
0
Normal stop
□
□
□
□
1
Compressorrun
■
□
□
□
2
Compressor overload protection
☆
□
□
□
3
Discharge protection
□
■
□
□
4
Outdoor unit overload protection
■
■
□
□
5
High pressure protection
☆
■
□
□
6
Over current protection
□
☆
□
□
7
IMP protection
■
☆
□
□
8
IMP over heating protection
☆
☆
□
□
9
PFC protection (including PFC overheating protection)
□
□
■
□
10
Phase current protection
■
□
■
□
11
Over voltage protection
☆
□
■
□
12
Insufficient voltage protection
□
■
■
□
13
Start failure
■
■
■
□
14
Compressor desynchronizing
☆
■
■
□
15
Compressor phase-lacking protection
□
☆
■
□
16
Compressor phase current detection malfunction
■
☆
■
□
17
Memory chip mistake
☆
☆
■
□
18
DC power supply circuit-short
□
□
☆
□
