4. Troubleshooting► Error CodeA1–4310► Error messageMotor Failure: #A1-4310. Turn off then on. Call for service if the problem persists► SymptomThe contact of ITB Unit is abnormal. / The resistance value of the first transfer roller is abnormal.► Troubleshooting method1) Enter SVC mode. Select the T1 engage motor test. (Diagnostics > Engine Diagnostics > Engine Test Routines >100–0080)Push the start button and check the motor operation.2) If the motor is not operational,a) Open the side cover. Check if the ITB connector is connected correctly or is deformed.b) If the harness is defective, replace it.c) Remove the ITB unit from the machine. Check if the photo interrupter sensor is contaminated or assembledproperly.d) If the photo sensor is defective, replace it.e) If the motor is operational but the engage gear is not operational, replace the main drive unit(JC93-00723A).3) If there is a motor noise or the motor is not operational normally, check the following :a) Remove the rear cover. Check if the T1 engage motor in the main drive unit is defective.i) Rotate the motor manually.4-77 Copyright© 1995-2016 SAMSUNG. All rights reserved.