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 are not part of the radio system. Such examples are aftermarket electrical accessories or other items which may generate noise in the vehicle electrical system.
Reference Information
Schematic Reference
Radio/Navigation System Schematics
Connector End View Reference
Entertainment/Communication Connector End Views
Description and Operation
Radio/Audio System Description and Operation
Electrical Information Reference
Scan Tool Reference
Scan Tool Data List
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 FM, AM, and XM (if equipped) stations, and play a known good CD.
Circuit/System Testing
Antenna Circuit Testing
- Disconnect the harness connector at the antenna.
- Ignition ON, radio ON, verify a test lamp illuminates between the entertainment remote enable signal circuit terminal 1, and ground.
⇒ | If test lamp does not illuminate, test the circuit for short to ground or an open/high resistance. If circuit tests normal, replace the radio. |
- Disconnect the antenna coax from the radio and the radio antenna module.
- Test for infinite resistance between the antenna coax center terminal and ground.
⇒ | If less than the specified value, replace the antenna coax. |
- Test for less than 5 ohms of resistance on the antenna coax center terminal from end to end.
⇒ | If greater than the specified range, replace the antenna coax. |
- Test for less than 5 ohms of resistance on the antenna coax outer shield from end to end.
⇒ | If greater than the specified range, replace the antenna coax. |
- Test for infinite resistance between the coax center terminal and the outer shield.
⇒ | If less than the specified value, replace the antenna coax. |
- If all circuits test normal, replace the 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.