B2575 on 2015-2019 Chevrolet Silverado 2500: Headlamp Control Circuit Fault Causes and Fixes

What's Unique About the 2015-2019 Chevrolet SILVERADO 2500

The Silverado 2500 is a heavy-duty truck frequently equipped with aftermarket accessories like snowplows. The BCM on this generation is particularly sensitive to how these accessories are wired into the factory lighting system. As a result, B2575 is most famously triggered by incorrect snowplow wiring integration, an issue so common that General Motors has issued multiple Technical Service Bulletins (TSBs). TSB PIT5412D explicitly states, "This is not an issue with the truck's headlight system. Contact the snowplow manufacturer/upfitter for additional information on their headlight changeover system."

Diagnostic Flowchart

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

Symptoms You May Notice

• Headlights are inoperative or work intermittently.
• Headlights flicker, especially when switching between truck and plow lights.
• Unable to switch from factory headlights to snowplow headlights.
• Headlights remain on and drain the battery.
• High-beam or low-beam specific failure.
• Instrument cluster, radio, or HVAC displays may blank out or reset when operating the snow plow, a related symptom caused by voltage fluctuations.

Most Likely Causes

1. Improper Snowplow or Aftermarket Lighting Installation 🔴 High Probability As a heavy-duty truck, it's a common platform for snowplow upfitting. The factory BCM requires a specific wiring method for integration, and deviations cause faults.
   How to confirm: Visually inspect for any aftermarket wiring spliced into the headlight harnesses. Check if the issue occurs when switching to the plow lights. A technician should consult GM Upfitter Integration Bulletin #116 for correct schematics, which can be found on the official GM Upfitter website (gmupfitter.com).
   Typical fix: Rewire the snowplow lighting module and harness according to the official GM Upfitter guidelines. This ensures the BCM receives the correct signals and loads. This is an upfitter/aftermarket issue, not a GM vehicle fault.
   Est. part cost: $0-$150
2. Blown Headlight Fuse 🟡 Medium Probability Electrical shorts or surges, often from the underlying cause of the B2575 code, can blow the protective fuses.
   How to confirm: Locate the underhood fuse block. For 2015-2016 models, check the double fuse F59. For 2017-2019 models, check F58. These are often pink or light brown Miku 3 type fuses. Test the fuse for continuity.
   Typical fix: Replace the blown fuse. If the new fuse blows immediately, a short circuit is present and requires further diagnosis.
   Est. part cost: $5-$20
3. Damaged Wiring Harness or Connectors 🟡 Medium Probability
   How to confirm: Visually inspect the wiring harnesses leading to both headlights and the underhood fuse block. Look for chafed wires, corrosion in connectors, or loose pins. Pay close attention to the ground connections, as a poor ground can cause a wide range of electrical issues.
   Typical fix: Repair the damaged section of wire or replace the corroded connector. Ensure all connections are clean, secure, and properly grounded.
   Est. part cost: $10-$100
4. Faulty Body Control Module (BCM) ⚪ Low Probability
   How to confirm: This should be the last step after all other possibilities (wiring, fuses, aftermarket hardware) have been ruled out. A professional will use a scan tool to monitor the BCM's commands to the headlight circuit. If the BCM is not sending the ground command despite the switch input, it may be faulty.
   Typical fix: Replace the Body Control Module. The new BCM will require programming by a dealership or a qualified shop to match the vehicle's options.
   Est. part cost: $300-$600

Rare But Worth Checking

• Faulty Headlight Switch: While possible, it's less common than wiring or BCM issues on this platform. If the BCM doesn't see the 'on' signal from the switch via a scan tool, the switch could be the culprit.
• Faulty Ambient Light Sensor: A faulty ambient light sensor can cause issues with automatic headlight operation, but it is less likely to set a B2575 circuit code. It's more likely to cause erratic behavior in 'Auto' mode.

Diagnosis Steps

1. Check for any aftermarket equipment, especially a snowplow package. If present, this is the most likely area of concern.
2. Scan the BCM for fault codes. Note if B2575 is present alone or with B2699.
3. Inspect the headlight fuses in the underhood fuse block (F59 for '15-'16, F58 for '17-'19). Replace if blown.
4. If a snowplow is installed, disconnect its lighting module to see if the fault clears and the factory headlights begin working normally. If they do, the plow wiring is the issue.
🎬 Watch this guide on fixing common Western snow plow lighting issues.
5. Consult GM Upfitter Bulletin #116 via the gmupfitter.com website to verify the plow wiring is installed correctly. Correct any deviations.
6. If no plow is present, inspect the headlight wiring harnesses from the BCM/fuse block to the headlight assemblies for any signs of damage, corrosion, or loose connections. Check grounds carefully.
7. Use a multimeter to check for proper voltage and ground at the headlight connector when the lights are commanded on. You should see battery voltage on the supply wire and a good ground provided by the BCM on the control wire.
8. If all wiring and fuses are good, use a capable scan tool to clear the codes. In some cases, the BCM may disable the circuit after a fault and needs to be reset.
9. If the code returns immediately and all wiring is confirmed good, the final step is to diagnose the BCM itself, which is best left to a professional.

Parts You'll Likely Need

• Snowplow Wiring Harness/Adapter — Often the cause is an incorrect or faulty aftermarket harness. Replacing it with one that is compliant with GM's electrical architecture is the fix.
  Trusted brands: Fisher, Western, Boss, Meyer
  OEM price range: $100-$300
  Aftermarket price range: $75-$250
• Body Control Module (BCM) (OEM #13595583, 13528945 (for 2017-18), 13528941 (for 2019). Note: Part number is VIN specific, always verify with a dealer.) — If wiring and other components are confirmed good, the BCM's internal driver for the headlight circuit may have failed. This is a last resort replacement and requires programming.
  Trusted brands: ACDelco (Genuine GM)
  OEM price range: $300-$600
  Aftermarket price range: $200-$450
• MCase or Miku 3 Fuse — This specific type of double fuse protects the headlight circuits and can blow due to a short.
  Trusted brands: Bussmann, Littelfuse
  OEM price range: $5-$20
  Aftermarket price range: $5-$15

Related Codes That Often Appear With This One

• B2699 — This code relates to the Right Headlamp Control Circuit. It is frequently set along with B2575 (Left Headlamp Control Circuit), especially in cases involving snowplow wiring issues, as both left and right headlight circuits are affected by the aftermarket module.

Technical Service Bulletins (TSBs) & Recalls

• PIT5412D: Addresses flickering or inoperative truck or snowplow headlights, mentioning codes B2575 and B2699 for 2014-2019 models. Explicitly states it's an upfitter issue and refers to bulletin 116.
• PIT5412C: An earlier version of the same bulletin for 2016 models with the same issue. [Referenced in PIT5412D]
• PIT5412A: An even earlier version for 2015 models, specifically calling out inoperative snowplow headlamps and directing technicians to GM up-fitter bulletin 116.
• GM Upfitter Bulletin #116: The core document detailing the correct methods for integrating aftermarket equipment with the vehicle's electrical system to prevent codes like B2575.

Platform-Specific Known Issues

• The primary vehicle-specific issue is the conflict between aftermarket snowplow lighting systems and the factory BCM, as documented in multiple GM Technical Service Bulletins.
• The official GM guidance directs technicians and upfitters to GM Upfitter bulletin #116 for the correct wiring procedures to avoid this fault. The resource is available at www.gmupfitter.com.

Mechanic-Grade Diagnostic Values

• BCM Operating Voltage — expected: 9.0 - 16.0 Volts. Failure: Operating outside this range can cause erratic BCM behavior and set various codes.

Hidden / Shadow Codes Worth Checking

• B2575 01: Left Headlamp Control Circuit Short to Voltage (see via A professional scan tool like GM GDS2 can read these sub-codes.)
• B2575 02: Left Headlamp Control Circuit Short to Ground (see via A professional scan tool like GM GDS2 can read these sub-codes.)
• B2575 04: Left Headlamp Control Circuit Open Circuit (see via A professional scan tool like GM GDS2 can read these sub-codes.)

Scan Tool Commands That Help

• GM GDS2 (Global Diagnostic System 2): Headlamp Output Control — This bidirectional control allows a technician to command the left headlamp ON and OFF directly from the scan tool. It is the definitive test to isolate the fault. If the headlamp works using this command after disconnecting an aftermarket accessory (like a plow), it proves the truck's BCM, wiring, and headlamp are all functional, and the fault is in the accessory.
• GM GDS2 (Global Diagnostic System 2): Clear All DTCs — After a fault is detected, the BCM may disable the headlamp driver circuit to protect it. After performing a repair or disconnecting a faulty aftermarket module, the codes must be cleared to re-enable the circuit and confirm the fix.

Wiring & Ground Locations

• BCM Connector X5, Pin 12 — The Body Control Module (BCM) is located in the cabin, typically behind the driver's side of the dashboard. Connector X5 is one of the several large connectors on the BCM.. This specific pin is the 'Left Low Beam Headlamp Control' circuit. The BCM provides a ground signal on this pin to activate the left low beam. Technicians can test for a ground signal here during diagnosis. The wire is typically Yellow/Gray.
• G100 / G101 — G100 is located on the lower left (driver's side) of the radiator core support. G101 is on the lower right (passenger's side).. These are primary forward chassis grounds. While not directly for the control circuit, a poor ground at these locations can cause a voltage differential, leading to flickering lights and a host of other electrical issues in the front of the vehicle.
• G103 / G104 — These are major engine block and cylinder head grounds, typically found on the front or rear of the cylinder heads.. The entire electrical system relies on a solid engine-to-chassis ground connection. A compromised ground here can cause the BCM to behave erratically and may contribute to setting circuit codes.
• Underhood Fuse Block (X50A) — Located in the engine bay, typically on the driver's side.. This fuse block is the power distribution center for the headlight circuits. The fuses (F59/F58) are located here, and the wiring from the BCM passes through its connectors. Corrosion or damage to the fuse block or its connectors can cause an open circuit or high resistance.

OEM Part Supersession History

• 13599685 → 13528941 — Standard part revision and update by the manufacturer.
  Heads up: The new part number (13528941) is the correct service replacement for the original. Both require programming by a dealer or qualified technician with GDS2 to match the vehicle's configuration.
• 22869158 → 22853757 — Part revision for the Headlamp Control Module/Ballast used on HID/LED equipped models.
  Heads up: This is a separate module from the BCM, used only on trucks with factory HID or LED headlamps. It also requires programming. It is not the cause of B2575 on a halogen-equipped truck.

Model Year Variations Within This Range

• 2015-2019: Headlight technology (Halogen, HID, LED) varies significantly by trim level and year. They are not interchangeable without wiring modification and BCM reprogramming. B2575 is most common on base halogen systems where plow lights are added.
• 2015-2016 vs 2017-2019: The underhood fuse block layout changed slightly. The fuse for the left headlamp is F59 on 2015-2016 models and F58 on 2017-2019 models, though their function is identical.