Fault codes covered
54-01
The discharge thermistor is used to protect the compressor and ensure discharge superheat is present at all times. When “ODT Open” malfunction is active 47 will be substituted by default. The sensor is monitored continuously and if resistance is above 310kohm for 1 second this malfunction will occur. Once sensor value drops below 310kohm for 1 second the malfunction will clear. Since achieving discharge superheat is an integral requirement for startup, when this sensor does not read a valid value, the system will only run at startup speed. Normal operation will resume once valid ODT value is read by PCM.
Measure resistance value of thermistor at the PCM connector. If value is above 310kohm, and OAT and OCT measure above 25F, look for a break in the wiring or at the connector itself. If no breaks are observed, replace sensor. If measured resistance is within allowable range, replace PCM.
Source: ACHPVSR454-02SM troubleshooting pages.