If you are hearing the door latch click, but it is not opening, it could be that the door is binding on the latch or body. Have a friend pull gently at the door when depressing the release to see if it opens.
If not, you'll need to seek help locally.
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RepairPal Certified shops can diagnose and repair your 2002 INFINITI QX4. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.