B2462 on 2015-2018 GMC Sierra 1500: GPS Antenna Failure, Causes, and Fixes

What's Unique About the 2015-2018 Gmc SIERRA 1500

The K2XX platform, which includes the 2014-2019 Sierra, Silverado, and full-size SUVs, is known for this specific issue. The gasket at the base of the 'shark fin' antenna is prone to failure, allowing water to leak into the cab and, more importantly, into the antenna's internal electronics. This corrosion is the root cause of the failure. The original antenna design featured a rear-facing drain hole that could trap water inside while driving; updated parts move this drain to the front. GM acknowledged this design flaw in multiple Technical Service Bulletins (TSBs), including #17-NA-214, which outlines the problem and the official repair.

Diagnostic Flowchart

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

Symptoms You May Notice

• GPS navigation showing incorrect location, no signal, or a 'GPS Signal Lost' message with a crossed-out GPS icon.
• SiriusXM radio has 'No Signal' message or cuts out frequently.
• OnStar status light is red 🎬 Watch: How these symptoms and the B2462 code appear together. or services are unavailable.
• Visible water stains on the headliner, particularly near the overhead console, sun visors, or A-pillar trim.
• Water dripping from the overhead console area or microphone grille.
• A dead battery, which can be caused by the water leak traveling down the A-pillar wiring and causing corrosion in the Left Hand Instrument Panel Body Electrical Center (fuse box).

Most Likely Causes

1. Failed Roof Antenna Assembly 🔴 High Probability As documented in GM TSBs #17-NA-214 and #PIT5362B, the original antenna's gasket fails, allowing water to enter and corrode the internal circuit board. Updated parts have a relocated drain hole at the front to help prevent water from being trapped inside.
   How to confirm: Check for the combination of symptoms (GPS/XM/OnStar failure) and look for water stains on the headliner. The presence of codes B2470 or B125C alongside B2462 strongly points to antenna failure. Physical inspection after removing the antenna will reveal obvious signs of corrosion or moisture inside the housing.
   Typical fix: Replace the entire roof antenna assembly. TSB #17-NA-214 recommends applying a bead of clear automotive seam sealer to the new gasket to prevent future leaks. This is considered the permanent solution.
   Est. part cost: $80-$200
2. Damaged Antenna Coaxial Cable ⚪ Low Probability
   How to confirm: After lowering the headliner to access the antenna, visually inspect the cable for any pinches, frays, or corrosion at the connection points to the antenna and where it connects to the radio/telematics module.
   Typical fix: Repair or replace the damaged section of the cable. If corrosion is present at the connector, cleaning may be possible, but replacement is often more reliable.
   Est. part cost: $20-$50

Rare But Worth Checking

• Faulty Radio or Telematics Module: This is very unlikely. The antenna assembly is the point of failure in the vast majority of cases for this specific code and vehicle. Only consider this after replacing the antenna and verifying all wiring is intact.

Diagnosis Steps

1. Confirm the trouble code B2462 using an OBD-II scanner. Check for related codes like B2470 and B125C.
2. Verify symptoms: Test the GPS, OnStar, and SiriusXM radio functions.
3. Inspect the interior headliner, especially around the overhead console and sun visors, for any signs of water stains or dampness.
4. Perform a water test by carefully running water from a hose over the roof antenna base. Have an assistant inside watch for any drips from the overhead console or A-pillar.
5. Carefully lower the front of the headliner. This involves removing the sun visors (T15 Torx screws), their clips, and the A-pillar grab handles (often 10mm bolts). Use plastic trim removal tools to avoid damage.
6. Disconnect the antenna's electrical connectors and unbolt the single 10mm nut 🎬 Watch this walkthrough on removing the shark fin antenna. holding the antenna to the roof.
7. Remove the antenna and inspect its base and the internal connectors for any green or white corrosion, which confirms water damage.
8. If water damage is confirmed or all other symptoms point to the antenna, replace the entire antenna assembly.

Parts You'll Likely Need

• High Frequency Antenna Assembly (OEM #84546524) — This is the complete 'shark fin' unit that fails due to internal corrosion from a water leak. It is the direct cause of code B2462. Part numbers are frequently updated and are color-specific, so always verify with a VIN. The original part number was often 23258460, which has been superseded multiple times.
  Trusted brands: ACDelco, GM Genuine Parts
  OEM price range: $80-$200
  Aftermarket price range: $50-$120
• Clear Automotive Seam Sealer — TSB #17-NA-214 explicitly recommends applying this to the new antenna's gasket to create a waterproof seal and prevent a repeat failure. Note that an earlier TSB, PIT5362B, advises against it, but the later bulletin and consensus from repair forums favor using a sealer for a permanent fix.
  Trusted brands: Kent Automotive High-Tech Clear Seam Sealer, 3M Clear Seam Sealer
  OEM price range: $20-$40
  Aftermarket price range: $15-$30

Related Codes That Often Appear With This One

• B2470 — This code means 'GPS Antenna Circuit Open' and is often set with B2462 because the internal corrosion from the water leak creates an open circuit inside the antenna.
• B125C — This is a more general antenna circuit malfunction code that is also cited in the TSBs and points to the same root cause of water intrusion and electronic failure within the antenna assembly.

Technical Service Bulletins (TSBs) & Recalls

• #17-NA-214: The most definitive TSB, it addresses customer concerns of OnStar, XM, or GPS malfunction, and/or a water leak at the headliner. It directly links these issues to DTCs B2462, B2470, or B125C and recommends replacing the antenna and applying Kent Automotive seam sealer.
• #PIT5362B: An earlier Preliminary Information bulletin that also addresses inaccurate GPS location and DTC B2462. It recommends replacing the antenna due to water intrusion but advises against using additional sealant on the new part. This advice was superseded by TSB 17-NA-214.

Platform-Specific Known Issues

• A known water leak from the roof antenna base is the primary issue, as documented in TSB #17NA214. This leak not only damages the antenna electronics causing code B2462, but can also stain the headliner and, in some cases, lead to a battery drain if water migrates down the A-pillar to the instrument panel fuse block (BEC).

Mechanic-Grade Diagnostic Values

• Voltage supplied to antenna internal amplifier — expected: 5 V. Failure: Voltage significantly lower than 5V or 0V could indicate a short or open circuit.
• System voltage for module operation — expected: 9 V to 16 V. Failure: DTC may not set or module may not operate correctly if system voltage is outside this range.

Hidden / Shadow Codes Worth Checking

• B2462 04: Global Positioning System (GPS) Open Circuit. This is the most common failure type, indicating a break in the antenna circuit, typically caused by internal corrosion from water damage. (see via Requires a professional scan tool like the GM GDS2 to view the two-digit symptom code (also called a failure byte).)
• B2462 02: Global Positioning System (GPS) Short to Ground. This indicates the module has detected that the antenna's signal circuit is shorted to ground. (see via Requires a professional scan tool like the GM GDS2 to view the two-digit symptom code.)
• B2462 01: Global Positioning System (GPS) Short to Battery. This indicates the module has detected a short to B+ on the GPS antenna signal circuit. (see via Requires a professional scan tool like the GM GDS2 to view the two-digit symptom code.)

Scan Tool Commands That Help

• GM GDS2: Module Diagnostics -> Telematics Communication Interface Control Module -> DTC Information — Use this to read the specific B2462 fault along with its crucial two-digit symptom code (e.g., -02, -04) to confirm the electrical fault type before disassembly.
• GM GDS2: Module Diagnostics -> K115 Telematics Communication Interface Control Module -> Data Display — After replacing the antenna, monitor PIDs like 'GPS Signal Status' or 'Number of Satellites Tracked' to verify the new part is working correctly before reassembling the headliner.
• EL-49903 GM OnStar Antenna Diagnostic Tool Kit: Substitute a known-good test antenna — This special tool can be connected directly to the telematics module (VCIM) or radio to bypass the vehicle's antenna and wiring. If the system functions correctly with the test antenna, it confirms the fault lies in the original antenna or its coaxial cable.

Wiring & Ground Locations

• K115 or K73 — The Telematics Communication Interface Control Module (VCIM), which processes the GPS signal, is often located behind the glove box or instrument panel.. This module sets the B2462 code. Verifying a clean, dry connection at this module is a key diagnostic step if a new antenna does not solve the issue.
• LH I/P BEC — Left Hand Instrument Panel Body Electrical Center (the interior fuse box on the driver's side of the dashboard).. TSB #17-NA-214 specifically warns that water from the leaking antenna can migrate down the A-pillar wiring and cause corrosion in this fuse box, leading to a battery drain or other electrical issues unrelated to GPS function.
• HMI Module — The Human Machine Interface module is located behind the glove box compartment.. This module controls the infotainment screen. The GPS antenna coaxial cable connects to this module, making it a primary point to check for corrosion or loose connections.

Real Owner Repair Stories

• YouTube channel 'TruckNerd' (GMC Yukon (K2XX Platform, same as Sierra)) — GPS not working on the radio, OnStar light was red, and XM radio was not working. Visible water stain on the headliner near the A-pillar.
  ❌ Tried (didn't work) The video directly proceeds to the correct fix, as the symptoms were classic for this known issue.
  ✅ What actually fixed it Replaced the entire roof 'shark fin' antenna assembly and applied a bead of seam sealer around the new gasket. The video highlights the design change in the new part, with the drain hole moved from the top/rear to the bottom/front to prevent water from being held inside. This resolved all symptoms, turning the OnStar light green and restoring GPS function.

OEM Part Supersession History

• 23258460 (and others) → Multiple, e.g., 84544674, 84546524 — The original antenna design had a flawed gasket and a rear-facing drain hole that allowed water intrusion, causing internal corrosion. Updated parts feature an improved seal and a front-facing drain hole.
  Heads up: Parts are color-specific. TSB PIT5362B notes that the service strategy changed from providing a black, paint-to-match antenna to providing pre-painted, color-coded antennas. Always verify the correct part number for the vehicle's color and VIN.

Model Year Variations Within This Range

• 2016-2018: For the 2016 model year, GM introduced a mid-cycle refresh that updated the infotainment system with a new HMI module to support Apple CarPlay and Android Auto. While the antenna failure is identical, the specific part number for the HMI module reporting the fault will differ from 2014-2015 models.
• 2015: The initial Preliminary Information bulletin (PIT5362B) was targeted at 2015 models built before specific dates in early 2015, indicating the problem was identified and addressed early in the generation's production run.