The Office of Defects Investigation (ODI) opened this investigation on February 9, 2012 in response to complaints alleging driver door module melting and/or burning in MY 2006-2007 Chevrolet Trailblazers. In response to ODI's Information Request letter, General Motors presented 167 reports and 698 warranty claims that related to the alleged problem. ODI has received a total of 83 complaints, 66 alleging the door module had melted or burned, and the remaining 17 stating that the window switches acted erratically or were inoperative. Twenty-eight of the reports received have led to driver door fires, some of which allege the vehicle was keyed off and unattended. Based on the agency's current analysis, ODI has upgraded its investigation to an Engineering Analysis (EA12-004) to determine whether the subject vehicles contain a defect that presents an unreasonable risk to safety.The vehicle models and production dates of affected vehicles will be evaluated, particularly other GMT360 vehicles. The ODI reports cited above can be reviewed online at www-odi.nhtsa.dot.gov/owners/SearchNHTSAID under the following identification (ODI) numbers: 10247838, 10260600, 10274337, 10275626, 10284010, 10396958, 10406203, 10409023, 10414691, 10417938, 10423865, 10426281, 10434446, 10445657, 10447754, 10447757, 10447770, 10447788, 10447813, 10447831, 10447865, 10447880, 10447892, 10447938, 10447994, 10447996, 10447997, 10448028, 10448086, 10448138, 10448176, 10448201, 10448337, 10448455, 10448464, 10448478, 10448540, 10448900, 10448941, 10449150, 10449166, 10449169, 10449236, 10449722, 10450055, 10450202, 10450284, 10451584, 10451878, 10451918, 10452197, 10452301, 10452586, 10452743, 10452895, 10453161, 10453227, 10453261, 10453578, 10453746, 10453951, 10454196, 10454211, 10454539, 10454673, 10455122, 10455150, 10455279, 10455469, 10456285, 10456529, 10457116, 10457644, 10457811, 10458224, 10458485, 10458599, 10458743, 10458846, 10460062, 10460141, 10460732, 10460843