Diagnostic Procedure

If DTC U1255 is stored as a "HISTORY" and is the only code set, check Powertrain Control Module (PCM), Standard Body Module (SBM), Air Bag Module (SDM), and Electronic Brake and Traction Control Module (EBTCM) connectors power, ground, and serial data terminals for poor connections and repair as necessary. See WIRING DIAGRAM  . If multiple communication DTCs are set, perform Class 2 Data Link Connector System Check. See CLASS 2 DATA LINK CONNECTOR SYSTEM CHECK  under SYMPTOM TESTS.