Code 4 flags every temperature sensor reading under 660 ohms at once, a fault the manual points at the connector and the power module.
Model compatibility: Fisher & Paykel reuses codes across series and model years, so 4 may mean something different on another appliance or generation. Confirm this against your model’s documentation and record your full model number before acting.
Plain language
What this code means
All of the temperature sensors read outside the normal range, below 660 ohms.
Code 4 on an Active Smart refrigerator is not about a single sensor. The control has found every temperature sensor under 660 ohms in the same moment. It is the low-reading twin of code 3, and the service manual gives both the same treatment.
Order of checks in the manual
Primary: examine the 6-way RAST connector on the power module.
Secondary: reterminate that same 6-way RAST connector.
Tertiary: put in a new power module.
What a reading under 660 ohms tells you
These sensors are thermistors, so resistance drops as temperature rises. The hottest entry in the manual’s chart is 50 degrees C at 0.9106 kilohms, and 660 ohms sits below that. A value this low looks either hotter than the chart goes or like the sensor wires touching. Because all the sensors fail together, the manual starts at the shared connector and the module instead of any one probe.
The sensors involved
PC sensor: the fresh food compartment.
FC sensor: the freezer compartment.
Evaporator sensor, also called the defrost sensor.
A technician can read each temperature from diagnostic mode. Hold MODE and press the temperature UP button to enter it. The LEDs show a binary pattern: total the lit ones, then take away 40 to get degrees C. Pressing MODE leaves the mode, and it also quits by itself after 5 minutes.
What owners can do
Keep your hands off the connectors. A button press quiets the alarm. Watch food temperatures, since a refrigerator working from misread sensors may run warmer or colder than it should.
Neighbouring codes
Code 10 covers the fresh food sensor alone reading low.
Code 8 covers the evaporator sensor alone reading low.
Fisher & Paykel refrigerator repair in Los Angeles
Important safety warning. Do not attempt repairs involving electrical components, gas, water lines, refrigerant or sealed systems. Unplug the appliance if it is safe to reach the outlet, and leave internal diagnostics to a qualified technician.
Seeing this code on your Fisher & Paykel appliance?
Book a specialist visit for a clear estimate and approval before any repair.
