MRCOOL / DIY 5th Generation
PC 00 error code
The voltage signal sent from the IPM to the compressor drive chip is abnormal.
- Severity
- technician
- Verified
- Jul 18, 2026
What triggers it
The voltage signal sent from the IPM to the compressor drive chip is abnormal.
What to do
- Check wiring between the outdoor PCB and compressor; correct or replace wires and connectors if faulty.
- Check IPM installation; tighten screws and apply silicon grease if installation is not correct.
- Perform the manual's IPM continuity check; replace the IPM board or outdoor PCB when terminal resistance is not uniform.
- Check outdoor fan operation and outdoor ventilation; use the fan-speed troubleshooting procedure if needed.
- Measure compressor resistance; replace the compressor if resistance is not uniform, otherwise replace the outdoor PCB.
Which systems show it
- MRCOOL DIY 5th Generation single-zone 9k, 12k, 18k, 24k, and 36k D25 indoor/outdoor models listed in manual section 1.1.
Related codes
Technician scope
IPM board, compressor, outdoor PCB
Source
- Document
- data/sources/mrcool-diy5-service.pdf
- Section
- 4.7 TS09-S: IPM module protection diagnosis and solution
- Page
- 70