Friedrich FPHMR18A3A Service Manual page 85

Outdoor Fault Codes
Fault code Fault description
27 Expansion valve A (gas
pipe) sensor fault
28 Expansion valve B (gas
pipe) sensor fault
29 Expansion valve C (gas
pipe) sensor fault
30 Expansion valve D (gas
pipe) sensor fault
45 IPM fault
46 IPM and control board
communication fault
85
TROUBLESHOOTING
Possible reasons for
abnormality
"1. The wiring of the sensor
for the expansion valve A (gas
pipe) is connected loosely;
2. The sensor of the expansion
valve A (gas pipe) fails;
3. The sampling circuit fails."
"1. The wiring of the sensor
for the expansion valve B (gas
pipe) connect is connected
loosely;
2. The sensor of the expansion
valve B (gas pipe) fails;
3. The sampling circuit fails."
"1. The wiring of the sensor
for the expansion valve B (gas
pipe) connect is connected
loosely;
2. The sensor of the expansion
valve C (gas pipe) is fails;
3. The sampling circuit fails."
"1. The wiring of the sensor
for the expansion valve B (gas
pipe) is connected loosely;
2. The sensor of the expansion
valve D (gas pipe) fails;
3. The sampling circuit fails."
There are many reasons for
this failure. You can check
the driver board fault LED
to further analyze the fault
code of the drive board and
to learn about what leads to
the fault and how to operate
it. Specific information can be
seen in table 5, table 6.
"1.The cable between the
control board and the driver
board is connected loosely;
2.The cable between the
control board and the driver
board fails;
3.The driver board fails;
4.The control board fails."
How to deal with
"1. Reconnect the wiring of
the sensor for the expansion
valve A (gas pipe);
2. Replace the sensor for
the expansion valve A (gas
pipe);
3. Replace the outdoor
control board."
"1. Reconnect the wiring of
the sensor for the expansion
valve B (gas pipe);
2. Replace the sensor for
the expansion valve B (gas
pipe);
3. Replace the outdoor
control board."
"1. Reconnect the wiring of
the sensor for the expansion
valve B (gas pipe);
2. Replace the sensor for
the expansion valve C (gas
pipe);
3. Replace the outdoor
control board."
"1. Reconnect the wiring of
the sensor for the expansion
valve B (gas pipe);
2. Replace the sensor for
the expansion valve D (gas
pipe);
3. Replace the outdoor
control board."
See attached "analysis of
the driving board fault".
"1.Reconnect the cable
between the control board
and the driver board;
2.Replace the
communication cable
between the control board
and the driver board;
3.Replace the driver board;
4.Replace the control
board."
Remarks