2012 Buick LaCrosse – 12-Volt Charging System Inoperative
- Aug 16
- 1 min read
CUSTOMER CONCERN
The 12-volt charging system is inoperative and DTCs P0AC4, U0293, and U1817 are stored.
CAUSE
The Hybrid Powertrain Control Module would not communicate even though its power and ground circuits were present, DLC terminals 6 and 14 measured 60 ohms, and other high-speed GMLAN modules communicated normally. Testing confirmed an internal HPCM/Starter Generator Control Module failure.
CORRECTION
Remove and replace the Hybrid Powertrain Control Module/Starter Generator Control Module, program and configure the replacement module, clear DTCs P0AC4, U0293, and U1817, and verify 12-volt charging operation.