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Home >> Cadillac >> 1998 >> Seville SLS >> Repair and Diagnosis >> Body & Frame >> Body, Cab Control Systems >> Body Control Module >> Diagnosis & Testing >> DTC U1255: Class-II Initialization Error >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform BCM diagnostic system check. See BCM DIAGNOSTIC SYSTEM CHECK  . After performing system check, go to next step.
  2. Determine which module(s) on the Class-II data line caused DTC to set by checking Data Link Connector (DLC) circuit. Use scan tool to attempt and establish communication with suspect module(s). If scan tool communicates with affected module, go to next step. If scan tool does not communicate with affected module, go to step 4).
  3. Check and repair Class-II serial data line circuit No. 1807 (Purple wire) for intermittent conditions. See WIRING DIAGRAMS  . After repairs, perform BCM diagnostic system check. See BCM DIAGNOSTIC SYSTEM CHECK  .
  4. Determine cause of loss of serial data communication in suspect module. Repair as necessary. After repairs or after establishing module communication, go to next step.
  5. Turn ignition off. Reconnect components and connectors. Turn ignition on. Clear DTCs using scan tool. After clearing DTCs, perform BCM diagnostic system check. See BCM DIAGNOSTIC SYSTEM CHECK  .
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