air blows,a/c & heat, why doesn't the mode work, only blows feet and defroster on 2004 Chevrolet Tahoe

Always blows defroster and feet no matter what the setting

by in Purcellville, VA on June 12, 2012
2 answers 1 comment
ANSWER by on June 12, 2012
POSS BLEND DOOR STUCK OR BROKEN SEEK DIAG AND EST
ANSWER by on June 12, 2012
Mode door or motor that changes the door position may have failed. This problem can be diagnosed with a Tech 2 GM scanner. A few other scanners may be able to do it also but the higher end scanners are needed.
COMMENT by on June 12, 2012
Not just a OBD2 code reader.