B2699 on 2014 Chevrolet Silverado 1500: Right Headlight Circuit Fault Causes and Fixes

What's Unique About the 2014-2014 Chevrolet SILVERADO 1500

For the 2014 K2XX generation Silverado and its platform-mate, the GMC Sierra, this code is strongly associated with aftermarket snowplow installations. General Motors has issued multiple Technical Service Bulletins (TSBs) acknowledging that the truck's BCM is sensitive to the electrical load and timing of snowplow headlight changeover modules. The BCM performs a diagnostic self-check the moment it commands the headlights on. If an aftermarket plow module switches the lights *after* this brief check, the BCM misinterprets the subsequent current inrush as a short-to-ground and disables the circuit to protect itself, setting code B2699.

Diagnostic Flowchart

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

Generation note: This issue is prevalent across the entire K2XX platform generation (2014-2018/19) for both Chevrolet Silverado and GMC Sierra trucks, especially those with snowplow prep packages or aftermarket plow installations.

Symptoms You May Notice

• Right low-beam headlight is inoperative or flickers
• Snowplow headlights are inoperative or flicker.
• Headlight-related warning message on the instrument cluster
• The issue occurs specifically when switching from truck headlights to plow headlights.

Most Likely Causes

1. Faulty or Incompatible Snowplow Headlight Module/Wiring 🔴 High Probability As documented in GM TSBs (like PIT5412D) and Upfitter Integration Bulletin 116, the BCM in these trucks is highly sensitive to the electrical timing of aftermarket headlight switching modules used for snowplows. The delayed current draw from the module is misinterpreted as a short circuit.
   How to confirm: Disconnect the snowplow's main electrical harness from the truck. Clear the codes with a scan tool. If the factory headlights now work correctly and the code does not return, the fault is definitively within the snowplow's electrical system.
   Typical fix: Contact the snowplow manufacturer (e.g., Western, Fisher, Boss) for their specific diagnostic procedures. This often requires replacing the plow's lighting control module with an updated version. For many Western, Fisher, and SnowEx plows, the 3-port isolation module (Part #29070-1) 🎬 Watch: How to install a Western plow wiring module is a common fix. Some plow manufacturers also have specific harness kits to address this.
   Est. part cost: $150-$350 for a new plow-side lighting module/harness kit.
2. Open or Short in Factory Headlight Wiring Harness ⚪ Low Probability This can happen on any vehicle due to chafing, corrosion, or impact damage, but it's a much less common cause for this specific code on this truck compared to plow issues.
   How to confirm: With the snowplow harness disconnected, visually inspect the factory wiring to the right headlight assembly for damage. Use a digital multimeter to check the control wire for continuity (to find an open) and for a short to ground or voltage.
   Typical fix: Repair the damaged section of the wiring harness.
   Est. part cost: $5-$50 for wiring repair supplies.
3. Burnt-Out Right Low-Beam Headlight Bulb ⚪ Low Probability While a burnt-out bulb is a common maintenance item, it usually sets an 'open circuit' fault. On this platform, the BCM's sensitivity often points to the more complex plow integration issue first.
   How to confirm: Visually inspect the bulb's filament. If the filament is broken, the bulb is bad. Swap the right and left low-beam bulbs to see if the problem moves to the other side.
   Typical fix: Replace the right low-beam headlight bulb (Part type HIR2/9012).
   Est. part cost: $20-$60 for an aftermarket bulb, $40-$100 for an OEM bulb.

Rare But Worth Checking

• Faulty Body Control Module (BCM): This is extremely rare and should only be considered after all other possibilities, especially snowplow equipment and all wiring, have been exhaustively tested and ruled out. GM TSBs explicitly state that the BCM should not be replaced for this condition.

Diagnosis Steps

1. Read the trouble codes from the Body Control Module (BCM) with a capable OBD-II scanner.
2. If a snowplow is installed (or was previously), completely disconnect its electrical harness from the truck's factory wiring. This is the most important first step.
3. Clear all DTCs using the scan tool.
4. Turn the headlights on and check for normal operation. If the factory lights work and code B2699 does not return, the fault is confirmed to be in the the snowplow's electrical system.
5. If the fault is in the plow system, inspect the plow's wiring harness for corrosion or damage. Consult the plow manufacturer for the correct, updated lighting module or harness kit for a 2014 GM truck. For Western/Fisher, this is often the 3-port isolation module #29070-1.
6. As a temporary workaround or test, some plow manufacturers (like BOSS in service bulletin SV112) suggest turning the truck's headlight switch completely OFF before using the plow controller to switch between truck and plow lights.
7. If the code returns with the plow disconnected, the fault is in the truck's factory system. Turn the ignition off.
8. Inspect the right low-beam headlight bulb (HIR2/9012) and its connector for damage or corrosion.
9. If the bulb and connector are good, inspect the wiring harness leading to the right headlight for any signs of physical damage, chafing, or melting.
10. Using a digital multimeter, test the right headlight control circuit for an open, a short to ground, or a short to voltage.
11. If all wiring and the bulb test normal, the BCM may be the issue, but this is highly unlikely and should be the last resort.

Parts You'll Likely Need

• Snowplow Headlight Isolation Module (OEM #29070-1 (Western/Fisher/SnowEx 3-Port Module)) — This is the most common cause of B2699 on these trucks. The module and harness from the plow manufacturer are often incompatible or fail, triggering the fault in the truck's BCM. This specific part is frequently cited as the solution.
  Trusted brands: Western, Fisher, Boss, SnowEx
  OEM price range: $160-$250
  Aftermarket price range: $160-$250
• Low Beam Headlight Bulb (OEM #9012 (HIR2)) — A burnt-out bulb can cause an open circuit fault, though it is a less frequent cause for this code on plow-equipped trucks.
  Trusted brands: ACDelco, Sylvania, Philips
  OEM price range: $40-$100
  Aftermarket price range: $20-$60

Related Codes That Often Appear With This One

• B2575 — This is the corresponding code for the Left Headlamp Control Circuit. It frequently appears with B2699 when there is a systemic issue with an aftermarket snowplow's lighting module affecting both headlights.

Technical Service Bulletins (TSBs) & Recalls

• PIT5412D, PIT5412C, PIT5412A, PIT5412: All relate to inoperative or flickering headlights when a snowplow is installed, pointing to the aftermarket equipment as the cause for DTC B2699 and B2575. They explicitly state this is not an issue with the truck's system.
• GM Upfitter Integration Bulletin 116: Provides detailed information on the headlight circuits for proper integration of aftermarket equipment, explaining the BCM's sensitivity to delayed current draw from headlight switching.
• BOSS Snowplow Service Bulletin SV112: Acknowledges the issue on 2014+ GM trucks and provides a specific operating procedure (turning truck lights off before switching) to prevent the code from setting.

Platform-Specific Known Issues

• GM has issued multiple Technical Service Bulletins (e.g., PIT5412, PIT5412A, PIT5412C, PIT5412D) regarding this exact issue. They state that when B2699 and/or B2575 are set on vehicles with snowplow equipment, the cause is related to the aftermarket headlight changeover system. The bulletins direct technicians to consult GM Upfitter Integration Bulletin 116 and contact the snowplow manufacturer for support.
• GM Upfitter Bulletin #116 explains the technical reason: the BCM expects to see the current inrush from the headlight bulb immediately. Aftermarket modules that delay this signal cause the BCM to defensively shut down the circuit, believing it's a short to ground.
• BOSS Snowplow issued Service Bulletin SV112 which provides a temporary workaround: turn the truck's headlight switch to OFF before using the plow's rocker switch to change between truck and plow lights. This prevents the BCM from seeing the problematic delayed signal.

Mechanic-Grade Diagnostic Values

• Right Headlight Ground Circuit Resistance — expected: Less than 5 ohms. Failure: A reading greater than 5 ohms indicates high resistance or an open in the ground circuit.
• Right Headlight Control Circuit Resistance to Ground (Ignition OFF) — expected: Infinite resistance (O.L.). Failure: Any reading less than infinite resistance indicates a short to ground in the control circuit.
• Right Headlight Control Circuit Voltage (Ignition ON, Headlight OFF) — expected: Less than 1 Volt. Failure: A reading of 1V or greater indicates a short to voltage in the control circuit.

Hidden / Shadow Codes Worth Checking

• B2699 01: Right Low Beam Control Circuit Shorted to Battery (see via A professional-grade scan tool (like GM GDS2) that can read BCM symptom codes.)
• B2699 02: Right Low Beam Control Circuit Shorted to Ground (see via A professional-grade scan tool (like GM GDS2) that can read BCM symptom codes.)
• B2699 04: Right Low Beam Control Circuit Open (see via A professional-grade scan tool (like GM GDS2) that can read BCM symptom codes.)

Scan Tool Commands That Help

• GM GDS2 (or equivalent professional scanner): BCM Output Controls > Headlamp Controls — After disconnecting the snowplow harness, use this command to individually turn the right low beam headlight on and off. This directly tests the BCM's driver circuit and the factory wiring to the bulb, bypassing the headlight switch. If the light works with the scan tool but not the switch, it points to an input issue. If it fails to work, it confirms a fault in the output circuit or BCM driver.

Wiring & Ground Locations

• G101 / G107 — On the lower right side of the radiator support, in the engine compartment.. This is a primary grounding point for the front lighting system, including the right headlight. A corroded or loose connection here can cause high resistance, leading to intermittent or inoperative headlights and potentially triggering open circuit or performance codes.
• G103 — On the front corner of the passenger side cylinder head, just below the valve cover.. This is a major engine and chassis ground. While not directly for the headlight bulb, poor grounding here can introduce electrical noise and voltage discrepancies that affect sensitive modules like the BCM, contributing to a range of electrical faults.
• BCM Connector X5 — The Body Control Module (BCM) is located in the cabin, typically behind the driver's side of the dashboard.. The control wire for the right low-beam headlamp originates at a specific pin on one of the BCM's multi-pin connectors (often labeled X4, X5, or X6 depending on the specific diagram). Probing this pin for voltage while commanding the light on/off with a scan tool is the definitive way to determine if the BCM is sending the signal, thus isolating the fault to either the BCM or the downstream wiring/headlight.

Real Owner Repair Stories

• YouTube Commenter on Garcia Garage video (2014-2018 Silverado/Sierra) — Stabilitrak code, flickering lights, and other electrical issues.
  ❌ Tried (didn't work) Cleaning grounds, Replacing steering position sensor, Dealer replaced a wheel hub
  ✅ What actually fixed it Replacing the main negative battery cable, even though it appeared to be in perfect condition. This resolved all electrical problems.

OEM Part Supersession History

• 29070 (or earlier incompatible modules) → 29070-1 — The 29070-1 module was released by Western/Fisher to be compatible with the sensitive BCM logic in 2014+ GM trucks. It correctly manages the headlight changeover timing to prevent the BCM from falsely detecting a short circuit.
  Heads up: Using an older plow module on a 2014 Silverado is a near-guaranteed cause of codes B2699 and B2575. The -1 revision is critical. Some newer trucks (2019+) may require different kits entirely, like the 72199-1.