Radio Poor Reception
Radio Poor Reception
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
Circuit/System Description
AM and FM radio reception is dependent on the following components:
* Radio antenna - part of the rear window
* Coax cable between the radio antenna and the radio antenna module
* Radio antenna module
* Coax cable between the radio antenna module and the radio
* Radio
Reference Information
Schematic Reference
Radio/Navigation System Schematics (Radio/Navigation System Schematics)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Radio/Audio System Description and Operation (Radio/Audio System Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Testing
Antenna Coaxial Cable Testing
Important: For steps 2-5, perform the tests on each of the disconnected coax cables.
1. Ignition OFF, disconnect all coax cables from the radio, radio antenna module, and the antenna.
2. Test for infinite resistance between the antenna coax center terminal and ground.
• If less than the specified value, replace the antenna coax.
3. Test for less than 5 ohms on the antenna coax center terminal from end to end.
• If greater than the specified range, replace the antenna coax.
4. Test for less than 5 ohms on the antenna coax outer shield from end to end.
• If greater than the specified range, replace the antenna coax.
5. Test for infinite resistance between the coax center terminal and the outer shield.
• If less than the specified value, replace the antenna coax.
Antenna Inspection
1. Ignition OFF, disconnect the coax cable from the antenna located on the rear window.
2. Verify the coax connectors are properly secured and free of any damage.
• If damage is found, repair or replace as necessary.
3. Inspect the antenna. Verify all branches of the antenna are intact, with no scratches or other damage.
• If damage is found, repair or replace as necessary.
Radio Antenna Module Test
1. Inspect the antenna module grounding surface and mounting hardware for any corrosion that may cause a poor ground.
• If corrosion is noted, clean the grounding surfaces and hardware.
2. Ignition OFF, disconnect the harness connector at the radio antenna module.
3. Radio ON, test for B+ between the signal circuit terminal 1 and ground.
• If less than the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.
4. If all circuits test normal, replace the antenna amplifier module.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Antenna Cable Replacement (Antenna Cable Replacement)
* Radio Antenna Module Replacement (Radio Antenna Module Replacement)
* Rear Window Replacement (Rear Window Replacement)
* Control Module References (Programming and Relearning) for Radio replacement, setup, and programming