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Error code reference
Samsung Air Conditioner Error Code P420
High pressure protection control-high pressure sensor value over 28 kg/cm²G.
SourceSamsung Air Conditioner - Service Manual: Troubleshooting (AVMC4H071EA)p. 12-72
Diagnostic procedure
The full P420 procedure
Step 1 is visible so you can confirm you are on the right page. The remaining steps, the ones that tell you whether to actually replace a part, unlock with any pass.
MyPros+ · DiagnosticsStep 1 preview
1
First diagnostic step
Check if all service valves are open; check PWM valve coil and connector.
SourceSamsung Air Conditioner - Service Manual: Troubleshooting (AVMC4H071EA)p. 12-72
More steps, wiring diagram references, and verified part numbers
Includes expected resistance and voltage values, connector pinouts, and supersession notes for replacement parts.
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Where this code is documented
2 manuals in the MyPros+ library document this code for Samsung air conditioner.
Models covered by the manuals that document this code
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