Fault Code Lookup

HVAC Sales Master
ERR.185.03
Compressor Dome Temp Protect — Low Hold
This code typically points to
  • Excessive compressor dome temperature protection

Next checks to confirm
  1. Hold response version of low-speed dome-temperature control

Escalation
Compressor speed held
Reset behavior
Not explicitly exposed in accessible snippet.
Service Soon
Schedule repair
Deeper detail available
The manufacturer has pushed full per-code troubleshooting trees into the Trane Technician app. Use the app for subcode detail beyond what's shown here.
Source
Trane System Alert Guide p.42, public distributor-posted PDF