Symptom: Symptoms may include the interface not turning on, the factory radio not turning on (AP4-CH41 only), no audio or intermittent audio on one or more channels.
Cause: Pins pulling out of the JST connector that plugs into the AP4 interface resulting in poor, or no connection of some circuits.
Solution: Locate pins that have pulled out of the connector and fully re-insert the pins into the harness.
If a pin has pulled completely out of the harness, see “AP4 Connector Diagrams” starting on page 2 for pinouts of each of the amp pro interfaces to find pin location information.
Follow the procedure outlined in this tech brief in order to understand the problem and how to fix it.