What It Means
Circuit B suction pressure transducer reading out of range.
Carrier Packaged Unit
Carrier Packaged Unit Error Code 93
Troubleshooting guide for the Carrier Packaged Unit system fault 93.
Possible Causes
- Damaged transducer wiring or lost 5V DC supply.
- Failed circuit B suction pressure transducer.
- Refrigerant pressure out of bounds.
Not sure which one it is — or if it's none of these? Try ACLogics today.
Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.
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Full Diagnosis
Suction Pressure Transducer Failure - Circuit B. Suction pressure is outside the valid range and the circuit cannot run while active.
All Recorded Causes
Check circuit B suction pressure transducer wiring and 5V supply. Measure transducer output voltage. Inspect for refrigerant system issues causing out-of-range pressure. Replace transducer if signal is incorrect.
Verify Before Replacing Parts
- Confirm the exact Carrier model family and outdoor packaged units context before acting on a generic code description.
- Verify airflow first, then confirm operating pressures and temperature relationship before adjusting charge, since check circuit B suction pressure transducer wiring and 5V supply.
- Look for restrictions, iced coils, or dirty heat-transfer surfaces that can mimic a charge problem, and separately confirm measure transducer output voltage.
- After the correction, run the system long enough to confirm the outdoor packaged units fault does not return under normal load.
Still unsure about this fault?
ACLogics walks you through Carrier Packaged Unit diagnostics step-by-step — so you confirm the cause before swapping parts.
