LEXIE } TECH TIPS Applications: 2008 — 2011 Chevrolet Tahoe Two-Mode Hybrid 2008 — 2011 GMC Yukon Two-Mode Hybrid 2009 — 2011 Cadillac Escalade Two-Mode Hybrid 2009 — 2011 Chevrolet Silverado Two-Mode Hybrid 2009 — 2011 GMC Sierra Two-Mode Hybrid Condition: The technician may find the following diagnostic codes stored in the system with the engine failing to start: C0531 C0895 C129F POAB9 P1AE4 P1A88 P1B05 P1B06 P16F9 U0073 U0074 U0125 U0410 U0895 U1818 U1866 Cause: The proper procedure needs to be followed when working on the high voltage battery, if not it will cause the vehicle to go into a safe mode and prevent starting. Correction: Follow the manufacturer’s recommended procedures which include: 1) Diagnose codes P1AE2-P1AE4, P1B05 and/or P1B06 first. These codes are initiated when the high voltage system has been serviced and a service part not fully seated such as the generator control module sight shield or the 2 wire connector at the transmission 3 phase cable cover. 2) Diagnose communication error codes U0073, U0074, U0125, U0410, U0895, U1818 and/or U1866 taking care to inspect the powertrain expansion bus and the high speed LAN bus. 3) Diagnose and check the vehicle’s 12V battery system. REV: 20110919 Courtesy of APRA TSB_1021.docx Dixie Tech Tips are intended for use by professional technicians, and are not for the general public. They are written to inform technicians of conditions that may exist or as a guide to aid in diagnosing and servicing a vehicle. All references to original equipment manufactures, vehicle manufactures and any other Trade Mark names are for the sole purpose of identifying the vehicle and or part that the Tech Tip applies to. This document is property of Dixie Electric Ltd. and is not to be copied or distributed with out written permission.