Rear Window Defogger Operation - keywords button control defog glass head HVAC stationary

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

A customer may notice that the rear defogger stays on for longer than 20 minutes. This is a normal operating characteristic of the vehicle.

First time the rear defogger button is pressed the defogger will stay on for 20 minutes. Each button press there after will keep the rear defogger on for 10 minutes.

If the Rear Window Defog has been requested ON and the vehicle speed goes over 44.7 MPH (72KPH) the rear defogger will stay on and the timer will be suspended, then resume counting down once the vehicle goes below 44.7MPH. At the end of the timer the rear window defog will automatically shut off.

After the vehicle speed goes below the 44.7 MPH the counter will resume countdown from however many minutes were left from the 20 minutes or 10 minutes accordingly and will not reset again during that cycle.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.