GM: SEE DOCUMENT SEARCH BUTTON FOR OWNER LETTER. PREMATURE TIMING CHAIN WEAR- REPROGRAM ENGINE CONTROL MODULE. VEHICLES EQUIPPED WITH A HFV6 ENGINE, UNDER CERTAIN DRIVING CONDITIONS, AND WITH EXTENDED OIL CHANGE INTERVALS, THE TIMING CHAIN COULD WEAR PREMATURELY AND CAUSE THE ILLUMINATION OF THE SERVICE ENGINE SOON LIGHT. *JS
