Carrier 38QUS012D8S Service Manual page 130

2.4.4.9. P0 Malfunction
Malfunction conditions
Possible causes
First, test the resistance between every two ports of U, V, the W of the IPM and P, N. If any of the results is 0
or close to 0, the IPM is defective. If not, follow the following procedure:
Electrical Control System
When the voltage signal te IPM sends to compressor drive
chip is not normal, the LED displays "P0" and the unit turns off.
Wiring mistakes
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Faulty IPM board
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Faulty outdoor fan assemby
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Compressor malfunction
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Faulty outdoor PCB
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Troubleshooting
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