Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Special Tools
EL-48028 Digital Radio Test Antenna
Circuit System Verification
With the vehicle outside in an area with an unobstructed view of the southern sky, tune to XM. Verify XM reception is clear and the No XM Signal
message is not displayed on the radio.
Circuit/System Testing
1. Ignition OFF, disconnect the antenna coax from the DRR. Connect the EL-48028 to the DRR.
2. Radio ON, tuned to XM, verify DTC B1259 is not set as current.
锟斤拷 If the DTC is current, replace the DRR.
3. Ignition OFF, reconnect the antenna coax to the DRR, disconnect the digital radio antenna coax from the digital radio antenna.
4. Ignition ON, test for 4.5-5.5 volts between the antenna coax center terminal and the coax outer shield.
锟斤拷 If not within the specified range, replace the antenna coax.
5. If all circuits test normal, replace the digital radio antenna.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Cellular Communications/Digital Radio Antenna Replacement (See: Accessories and Optional Equipment/Antenna/Antenna, Radio/Service
and Repair/Cellular Communications/Digital Radio Antenna Replacement)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for DRR replacement, setup, and programming
B1277
DTC B1277, B127C, or B127D
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provide an overview of each diagnostic category.
DTC Descriptors
DTC B1277 01
- Microphone 1 (LF) Input Signal Circuit Short to Battery
DTC B1277 02
- Microphone 1 (LF) Input Signal Circuit Short to Ground
DTC B1277 04
- Microphone 1 (LF) Input Signal Circuit Open
DTC B1277 1A
- Microphone 1 (LF) Input Signal Circuit Bias Level Out of Range
DTC B127C 01
- Microphone 2 (RF) Input Signal Circuit Short to Battery
DTC B127C 02
- Microphone 2 (RF) Input Signal Circuit Short to Ground
