Diagnostic Instructions
DTC Descriptors
DTC B2462
Global Positioning System Signal
For symptom byte information refer to Symptom Byte List.
Circuit Description
The navigation antenna is connected to the human machine interface control module by a shielded coaxial cable. The human machine interface control module supplies 5 V through the coax cable to power the internal antenna amplifier.
Conditions for Running the DTC
Conditions for Setting the DTC
B2462 01
The human machine interface control module detects a short to B+ on the GPS antenna signal circuit.
B2462 02
The human machine interface control module detects a short to ground on the GPS antenna signal circuit.
B2462 04
The human machine interface control module detects an open/high resistance on the GPS antenna signal circuit.
Actions Taken When the DTC Sets
Conditions for Clearing the DTC
Diagnostic Aids
The navigation antenna requires a clear line of sight to the sky to operate properly. The GPS may have limited, intermittent, or no reception near tall buildings or inside structures.
Reference Information
Schematic Reference
Radio/Navigation System Wiring Schematics (IOB) , Radio/Navigation System Wiring Schematics (IOR) or Radio/Navigation System Wiring Schematics (IO5/IO6) , or Radio/Navigation System Wiring Schematics (IOS/IOT).
Connector End View Reference
Component Connector End View Index
Description and Operation
Radio/Audio System Description and Operation (IO6) , Radio/Audio System Description and Operation (IOB) , or Radio/Audio System Description and Operation (IOS/IOT/IOU).
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Special Tools
EL-49903 OnStar Antenna Diagnostic Tool Kit
Circuit/System Testing
1. Ignition OFF/vehicle OFF, disconnect the navigation antenna coax cable connector at the K74 Human Machine Interface Control Module. Connect the EL-49903 GM OnStar antenna diagnostic tool kit to the K74 Human Machine Interface Control Module, place the test antenna on the roof of the vehicle.
2. Ignition ON/vehicle in Service Mode, infotainment system ON, navigation selected.
3. Verify DTC B2462 is not set or the NO GPS symbol is not displayed on the information display.
Replace the K74 Human Machine Interface Control Module.
4. Ignition OFF/vehicle OFF, disconnect the radio navigation coax cable at the.
5. Verify the radio navigation coax cable passes the coax cable component test. Refer to Component Testing.
Replace the coax cable
6. Test or replace the T2RR Antenna - Roof Rear.
Component Testing
CAUTION: Refer to Test Probe Caution.
NOTE: Before testing the coax cable, check the cable exterior for being pinched, cut, damaged, or having loose connections at the components, which can cause reception issues.
To prevent false reading when testing the center coax terminals, use care not to ground the test probe on the outer housing/shield.
Coax Cable Test
1. Ignition OFF, disconnect the coax cable at both components.
2. Test for less than 5 Ω between coax cable center terminal end to end.
Replace the coax cable
3. Test for less than 5 Ω between the coax cable outer shield end to end.
Replace the coax cable
4. Test for infinite resistance between the coax cable center terminal and the coax cable outer shield.
Replace the coax cable
5. All OK
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.