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Error code reference
Bosch Heat Pump Error Code L3
IPM module protection-control board failed, compressor failed, or abnormal pressure.
SourceBosch IDS 2.0 Split System Heat Pump - Full Service ManualSection 12.3.17, page 58
Diagnostic procedure
The full L3 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 power supply is stable; check for blockage in refrigerant pipe.
SourceBosch IDS 2.0 Split System Heat Pump - Full Service ManualSection 12.3.17, page 58
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
1 manual in the MyPros+ library documents this code for Bosch heat pump.
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