Samsung ProXpress M456x Series Service Manual page 170

4. Troubleshooting
► Error Code
A3–3212
► Error message
Sensor Failure: #A3-3212. Turn off then on. Call for service if the problem persists
► Symptom
Inner temperature sensor is defective.
► Troubleshooting method
1) Enter SVC mode. Execute sensor test to check its operation.
(Diagnostics > Engine Diagnostics > Engine Test Routines)
2) Measure the resistance value of the connector at both ends.
If the value is not in 47.5KΩ ~ 52.5KΩ (@ 25 ℃), replace the inner temp sensor.
3) If the sensor is normal, replace the main board.
4-60 Copyright© 1995-2017 SAMSUNG. All rights reserved.