B2462 on 2015-2018 GMC Yukon XL: GPS Antenna Fault Causes and Fixes

What's Unique About the 2015-2018 Gmc YUKON XL

This generation of GM full-size SUVs and trucks (Yukon, Tahoe, Suburban, Escalade, Silverado, Sierra) is known for this specific issue due to the design of the roof-mounted 'shark fin' antenna. The gasket at the base of the antenna is prone to failure, allowing water to leak into the vehicle and, more critically, into the antenna's internal electronics. This water intrusion corrodes the internal circuit board, leading to the B2462 fault. GM has issued multiple Technical Service Bulletins (TSBs), such as 17-NA-214 and PIT5362B, acknowledging this exact problem and providing a detailed repair procedure.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Inaccurate or no GPS location on the navigation display, sometimes showing a GPS symbol with a slash through it.
• "No GPS" or "GPS Signal Lost" message on the infotainment screen.
• Red indicator light on the OnStar button.
• Inability to connect to OnStar services or OnStar reporting an incorrect vehicle location.
🎬 Watch: A breakdown of these symptoms and the B2462 code.
• Poor or no satellite radio (SiriusXM) reception.
• Visible water stains on the headliner near the overhead console or sun visors.
• A weak or dead battery, caused by water running down the A-pillar and shorting electronics in the Left Hand Instrument Panel Body Electrical Center (LH I/P BEC).

Most Likely Causes

1. Failed Roof Antenna Assembly ('Shark Fin') 🔴 High Probability As documented in GM TSBs, the antenna assembly is highly susceptible to internal failure from water intrusion past its main seal. The water pools inside the housing and corrodes the internal electronics, causing an open or shorted circuit. Replacement antennas have an updated design with a relocated drain hole to mitigate this issue.
   How to confirm: After confirming no issues with the coaxial cable, the antenna is the default point of failure. The presence of water stains on the headliner is a strong indicator. When the old antenna is removed, it is often possible to hear water sloshing inside it.
   Typical fix: Replace the entire roof-mounted antenna assembly. 🎬 See this walkthrough on replacing the high frequency antenna. The updated procedure also includes applying a seam sealer around the roof opening before installing the new part to prevent future leaks. 🎬 Watch: How to fix the shark fin antenna water leak.
   Est. part cost: $110-$160
2. Water Leak at Antenna Base 🔴 High Probability The gasket that seals the antenna to the roof panel can compress, dry out, or crack over time, allowing water to seep into the cabin. This is the root cause of the antenna failure itself and can lead to other water-related damage inside the vehicle.
   How to confirm: Perform a water test on the roof around the antenna. Visually inspect the headliner directly below the antenna for any signs of staining or moisture.
   Typical fix: Replacing the antenna assembly includes a new gasket. TSB #17-NA-214 also recommends applying a specific clear seam sealer (Kent Automotive P/N 10200) to the roof panel before installing the new antenna for a more robust seal.
   Est. part cost: $15-$30 for sealant if not included
3. Damaged or Corroded Antenna Coaxial Cable/Connector ⚪ Low Probability If water has been leaking for a long time, it can travel down the antenna's wiring pigtail and corrode the connectors where they attach to the main harness under the headliner. In some cases, the corrosion can be visible on the connector pins.
   How to confirm: Partially lower the headliner to access the antenna's electrical connectors (often purple and yellow/maroon). Unplug them and inspect for any green or white corrosion or physical damage.
   Typical fix: Clean the connectors with an electrical contact cleaner if corrosion is minor. If the connector or wiring is heavily damaged, it may need to be repaired or replaced.
   Est. part cost: $5-$50 for connector repair parts

Rare But Worth Checking

• Faulty Radio or HMI Module: This is very unlikely compared to the antenna failure. The antenna and its wiring should always be diagnosed first before considering replacing the expensive Human Machine Interface (HMI) module or the radio unit itself. The TSBs from GM exclusively point to the antenna as the cause for this code.

Diagnosis Steps

1. Verify the complaint: Check for a 'No GPS' message on the navigation screen and a red light on the OnStar buttons.
2. Scan for DTCs to confirm B2462 and any related codes like B2470 or B125C. Note any two-digit symptom codes (e.g., -02 for Short to Ground, -04 for Open Circuit).
3. Perform a thorough visual inspection of the headliner, especially around the overhead console and A-pillars, for any water stains.
4. Carefully lower the front/rear of the headliner to gain access. This typically involves removing sun visors (T15 Torx screws), the overhead console (T15 or Phillips screws), and the A-pillar grab handles (10mm bolts).
5. Inspect the antenna's electrical connectors (often 2 or 3 plugs) for any signs of water damage or corrosion.
6. If no corrosion is visible, the most probable cause is an internally failed antenna assembly. Unbolt the antenna (typically a single 10mm nut) and shake it to listen for trapped water.
7. Replace the antenna assembly. Clean the roof surface thoroughly with a solvent like Acrysol before installation.
8. Per TSB #17-NA-214, apply a 4-5mm bead of clear automotive seam sealer (Kent Automotive P/N 10200 or equivalent) around the mounting hole on the roof before installing the new antenna to prevent future leaks.
9. Install the new antenna within 5 minutes of applying the sealer, tighten the 10mm mounting nut, and reconnect the electrical plugs.
10. Reinstall the headliner and trim pieces.
11. Clear the DTCs and verify the fix. The GPS should acquire a signal, and the OnStar light should turn green.

Parts You'll Likely Need

• High Frequency Antenna Assembly (OEM #84346784) — This is the complete 'shark fin' unit that fails due to internal water intrusion. It contains the receivers for GPS, OnStar, and SiriusXM. The part number 84346784 supersedes the older part 23258454 and features an improved design.
  Trusted brands: ACDelco, Genuine GM
  OEM price range: $120-$160
  Aftermarket price range: $70-$100
• Clear Seam Sealer (OEM #Kent Automotive P/N 10200) — Specifically recommended by TSB #17-NA-214 to create a waterproof seal between the new antenna and the vehicle roof, preventing a repeat failure.
  Trusted brands: Kent Automotive High-Tech Seam Sealer, 3M Clear Auto Seam Sealer
  OEM price range: $20-$30
  Aftermarket price range: $15-$25

Related Codes That Often Appear With This One

• B2470 — This code means 'Cellular Phone Antenna Circuit' fault and is often set alongside B2462, as both point to a failure in the multi-function antenna assembly. TSBs list them together.
• B125C — This is another code related to the GPS Antenna circuit ('GPS Antenna - Not Detected'). It is frequently mentioned in the same TSBs as B2462 and indicates a similar fault path within the same component.

Technical Service Bulletins (TSBs) & Recalls

• 17-NA-214: Addresses customer concerns of OnStar, XM, GPS, or antenna malfunction, and/or water leaks on the headliner. It specifically mentions B2462 and recommends replacing the antenna and using Kent Automotive P/N 10200 seam sealer.
• PIT5362B: Cites inaccurate GPS location and DTCs B2462, B2470, and B125C. It instructs technicians to replace the high-efficiency antenna with the latest part number due to internal water intrusion.

Platform-Specific Known Issues

• The primary issue is a systemic design flaw in the antenna's gasket, leading to water leaks. This is documented in TSB #17-NA-214 and #PIT5362B.
• Water leaking from the antenna can run down the A-pillar and cause other, more severe electrical issues, including damage to the Left Hand Instrument Panel Body Electrical Center (LH I/P BEC), leading to battery drain or other malfunctions.

Mechanic-Grade Diagnostic Values

• Voltage between the GPS coax center conductor and outer shield at the antenna connector. — expected: 4.0-5.5 volts. Failure: A reading outside this range suggests a faulty navigation radio.
• Resistance of the GPS antenna coax cable center conductor (end to end). — expected: Less than 5.0 ohms. Failure: Higher resistance indicates a break in the cable.
• Resistance between the GPS antenna coax center conductor and the outer shield. — expected: Infinite resistance (open circuit). Failure: Any reading less than infinite indicates a short in the cable.

Hidden / Shadow Codes Worth Checking

• B2462-02: Global Positioning System (GPS) Short to Ground. This indicates the module has detected that the antenna signal circuit is shorted to the vehicle's ground. (see via A professional scan tool like the GM GDS2 is required to see these two-digit symptom codes.)
• B2462-04: Global Positioning System (GPS) Open Circuit. This indicates the module has detected a break or high resistance in the antenna signal circuit. (see via A professional scan tool like the GM GDS2 is required to see these two-digit symptom codes.)

Scan Tool Commands That Help

• GM GDS2: Module Diagnostics -> Radio or Telematics Communication Interface Control Module -> DTC Information — This function is used to read the specific B2462 fault code along with its crucial two-digit symptom code (-02 or -04), which directs the diagnostic path toward either a short or an open circuit.
• GM GDS2: Clear All DTCs — Used after the repair is complete to erase the stored fault codes from all modules. The vehicle must then be driven to confirm the GPS acquires a signal and the code does not return.

Wiring & Ground Locations

• A11 Radio / Telematics Communication Interface Control Module (TCCM) — The radio/navigation module is located in the center stack of the dashboard, behind the infotainment screen. The TCCM (OnStar module) is often located behind the glove box or integrated with the radio.. This is the module that powers the GPS antenna and diagnoses the circuit. The coaxial cable from the antenna plugs directly into this module (or a splitter connected to it). Testing for voltage should be done at the module's antenna connector.
• Antenna Connectors — Located under the headliner, directly beneath the roof-mounted 'shark fin' antenna base. Access requires partially lowering the headliner.. These connectors (often yellow and purple/maroon) are a common point for corrosion if the antenna seal has been leaking. They must be inspected for water damage.

Real Owner Repair Stories

• YouTube video by '2016 GMC Yukon Denali GPS Antenna Replacement' (2016 GMC Yukon Denali) — GPS not working, implied OnStar issues.
  ✅ What actually fixed it The owner replaced the entire roof 'shark fin' antenna assembly. The video clearly shows the old part and the new, redesigned part, highlighting that the drain hole was moved to prevent water from being trapped inside. The fix was successful after installing the new antenna.

OEM Part Supersession History

• 23258454 → 84346784 — The original antenna design was prone to internal water intrusion and corrosion. The updated part (84346784) features a redesigned housing, including a relocated drain hole, to prevent water from pooling inside the unit.