Identifying Concerns

Refer to any Technical Service Bulletins. Also refer to the Dealer Communication System. The Dealer Communication System will provide any applicable Preliminary Information (P/I) for customer concerns.

Determine if any DTCs are stored. Refer to Computers and Control Systems. Computers and Control Systems

If the reception is poor, determine if the station is within the customer's listening area.

Before you test for audio reception or noise, position the vehicle outside of the building with the hood closed.

Duplicate the customer's complaint before you begin to diagnose the system:
^ Ask the customer to demonstrate the condition.
^ Compare the vehicle to another vehicle in order to determine if the condition is abnormal:
- Test drive the vehicle with the customer.
- Test drive another vehicle that is a similar model with a similar audio system.

Before you begin diagnosis, identify which components are involved and the features of these components. Determine if any aftermarket equipment has been installed on the vehicle. Complete the following steps if aftermarket equipment is present:
1. Disconnect the aftermarket equipment.
2. Determine if the customer's complaint still exists.
3. Reinstall the equipment as needed.

Complete the following steps in order to identify a faulty component:
^ Place the ignition into the following positions. Determine in which position the noise is audible:
^ The ACCESSORY position
^ The ON position, with the engine off
^ The ON position, with the engine running
^ Remove the fuses one at a time until the condition is gone.
^ Mark the fuse or fuses that cause the condition.
^ Reinstall all of the fuses and the circuit breakers.
^ Determine which systems and components are powered by the faulty fuse or fuses.
^ Disconnect each of the components that is powered by the complaint fuse or fuses. Disconnect the components one at a time.
^ When the condition is gone, identify the noisy component.
^ Inspect the ground integrity of the component that is causing the condition.

An interference condition may not be an audible noise.

Most noises can be heard on weak stations near the end of the band. These noises are normal.

An ignition noise on FM may indicate that the ignition system is flawed.

Malfunction in the following items may cause noise or poor reception:
^ The system components
^ The relays
^ The solenoids