Steering Wheel ON/OFF And Volume Controls Inoperative At Start Up - keywords backlight backlighting bus button communication control data delay ignition inop LED light navigation off on operation

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

Some customers may comment that the steering wheel, on/off and volume controls are inoperative for the first 10-15 seconds after the vehicle is started. This is due to serial data bus traffic of the vehicle's electrical system (data communication between modules). These controls have a low priority on this bus until all other modules on the bus are signed on and recognized.

If the switches work after 15 seconds, the radio should not be replaced because this is normal operating characteristics. Replacing the radio will not correct this concern. If a customer complains, the dealership should review the radio operation with the customer. When first started the volume and power switch will not operate for 10-15 seconds.

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.