i have a 2009 vw jetta only 3 doors lock my left back door does not lock
Are they electric locks? If they are wen u engage do you hear sound in three and not the one? If so could be motor, switch, or wiring? If you hear sound could be linkage inside. If manuel locks again could be linkage. You may have to take off panel and look and /or test motor, switch, etc. Try taking look at fuse too just in case.
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