For 1990-2009 cars only
Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC B1272 02: Antenna FM/AM Signal Circuit Low VoltageDTC B1272 04: Antenna FM/AM Signal Circuit Open
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Radio Antenna Coax | B1272 02 | B1272 04 | 1 | -- |
1. Poor radio reception | ||||
Circuit/System Description
AM and FM radio reception is dependent on the following components:
| • | Radio antenna |
| • | Coax cable between the radio antenna and the radio |
| • | Radio |
Conditions for Running the DTC
Radio ON
Conditions for Setting the DTC
A short to ground or an open/high resistance is detected on the radio antenna coax.
Action Taken When the DTC Sets
No action is taken when this DTC sets.
Conditions for Clearing the DTC
| • | A current DTC will clear when the conditions for setting the DTC are no longer present. |
| • | A history DTC will clear after 100 malfunction free ignition cycles. |
Reference Information
Schematic Reference
Radio/Navigation System Schematics
Connector End View Reference
Description and Operation
Radio/Audio System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
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.
- Ignition ON, test for 9.5-11.0 V between the center terminal at terminal 1 and ground.
- If all circuits test normal, replace the radio antenna.
| ⇒ | If greater than the specified range, test the antenna coax shield for an open/high resistance. If the coax test normal, replace the radio. |
| ⇒ | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
