AP 123 display and keypad issues

This guide covers AP 123 display and keypad issues. Fix display errors and unresponsive keypads.

• Check display harness seating.
• Inspect keypad for stuck keys.
• Power cycle and observe error codes.
• Replace display module if necessary.

• Perform a controlled test after each adjustment.
• Document the changes and results for future reference.
• If the issue persists, swap with a known-good component.

• Clean components during each service visit.
• Log repeat faults to identify wear patterns.
• Keep spare parts for legacy models on the truck.

• You have repeated failures after controlled testing.
• Safety or electrical issues are suspected.
• You need model-specific parts or OEM guidance.

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