Diagnostic Instructions
Circuit/System Description
AM and FM radio reception is dependent on the following components:
• | Coax cable between the radio antenna and the radio |
Diagnostic Aids
Poor AM and FM radio reception is dependent on multiple influences, some of which may not be vehicle related. Areas which have high RF traffic or block the signal path may cause a degradation in radio reception. Radio reception may also be influenced by
items within the vehicle, but not part of the radio system. Such examples are aftermarket electrical accessories or other items which may generated noise in the vehicle electrical system.
Reference Information
Schematic Reference
Radio/Navigation System Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Radio/Audio System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Inspect the antenna for proper mounting or physical damage.
⇒ | If damage is found, repair or replace as necessary |
- Radio ON, tune to several known AM and FM stations, and play a known good CD.
Circuit/System Testing
- Disconnect the harness connector at the radio antenna.
- Ignition OFF, test for less than 10 Ω between the outer shield at terminal 1 and ground.
⇒ | If greater than the specified range, test the antenna coax shield for an open/high resistance. If the coax test normal, replace the radio. |
- Ignition ON, test the center terminal at terminal 1 for 9.5-11.0 V
⇒ | If less than the specified range, test the antenna coax center terminal for a short to ground or an open/high resistance. If the coax tests normal, replace the radio. |
⇒ | If greater than the specified range, test the antenna coax center terminal for a short to voltage. If the coax tests normal, replace the radio. |
- If all circuits test normal, replace the radio antenna.
- Ignition ON, radio ON, verify radio reception has improved.
⇒ | If there is still poor reception, replace the radio. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.