Whirlpool Refrigerator Error Code CMP — Compressor Circuit Failure
What this means
The CMP error code on Whirlpool refrigerators indicates a compressor circuit failure. The main control board has attempted to start the compressor but detected an open circuit, locked rotor, or overload trip. The refrigerator will stop cooling. Common causes include a failed compressor start relay, a burned-out compressor winding, a tripped overload protector, or a wiring fault between the control board and compressor.
Step-by-step fix
4 stepsPower cycle and listen for compressor start
Unplug the refrigerator for 10 minutes, then plug it back in. Listen carefully for the compressor attempting to start — you should hear a hum followed by a steady running sound. If you hear clicking every few minutes, the compressor is trying to start but failing.
The clicking sound is the overload protector tripping, which indicates a start relay failure or a locked compressor.
Test the compressor start relay
Unplug the refrigerator. Pull the start relay off the compressor terminals (located at the rear bottom). Shake it — if it rattles, the internal contacts are broken and it needs replacement. Test for continuity between the start and run terminals.
The start relay is the most common cause of this error and is an inexpensive, easy replacement.
Test the compressor windings
With the relay removed, test resistance between the three compressor terminals: Start (S), Run (R), and Common (C). S-to-C plus R-to-C should equal S-to-R. All readings should be between 3 and 15 ohms. An open or shorted reading indicates a failed compressor.
Also test each terminal to the compressor housing (ground) — any continuity to ground means the compressor is shorted and must be replaced.
Check the overload protector
The overload protector is attached to the compressor next to the start relay. Test it for continuity with a multimeter. It should show continuity when cool. If it is open, it may be permanently tripped and need replacement.
The overload protector is often sold as a kit with the start relay. Replace both together for reliability.
When to call a professional
If the compressor windings test open or shorted, compressor replacement requires a licensed technician with refrigerant handling certification (EPA Section 608). Do not attempt to replace the compressor yourself.
Related error codes
Information compiled from manufacturer service manuals, official troubleshooting documentation, and appliance repair industry resources. This guide is for informational purposes only — always consult a qualified technician for complex repairs.
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