This bulletin applies to 2008-2009 Chevy Tahoe Hybrid and GMC Yukon Hybrid. Some customers may experience a no-crank/no start condition with DTC U1812 set.
Use the Tech 2 scan tool to clear the code. If the code clears and does not immediately reset during crank mode, follow the “no crank” diagnosis (Document ID 2010546 in Sl2000. DO NOT try to replace the battery pack to resolve this concern.
If you erase DTC U1812 and the trouble code resets without cranking for longer than three seconds, follow normal diagnostics in the service manual.