AutoCodes – GMC – B2600 GMC

B2600 GMC Code - Left Daytime Running Lamps Control Circuit

Quick Answer

The ambient light sensor is used to monitor outside lighting conditions. Common causes include Faulty Left Headlamp Assembly, Left Headlamp Assembly harness is open or shorted, Left Headlamp Assembly circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: B2600 GMC indicates Left Daytime Running Lamps Control Circuit.
Common causes: Common causes include Faulty Left Headlamp Assembly, Left Headlamp Assembly harness is open or shorted, Left Headlamp Assembly circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 2,499

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on May 26, 2023

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code B2600 GMC Description

The ambient light sensor is used to monitor outside lighting conditions. The ambient light sensor provides a voltage signal that will vary between 0.2 and 4.9 volts depending on outside lighting conditions. The Body Control Module (BCM) provides a 5-volt reference signal to the ambient light sensor and the Heating, Ventilation, and Air Conditioning (HVAC) control module provides a low reference ground. The BCM monitors the ambient light sensor signal circuit to determine if outside lighting conditions are correct for either Daytime Running Lights (DRL) or Automatic Lamp Control (ALC) when the headlamp switch is in the AUTO position. In daylight conditions, the BCM will command the DRLs ON. During low light conditions, the BCM will command the low beam headlamps ON. Any function or condition that turns on the headlamps will cancel the DRL operation. The Diagnostic Trouble Code (DTC) will be set when the BCM detects a problem in the left DRL control circuit.

OBDII Code B2600 GMC - Left Daytime Running Lamps Control Circuit - AutoCodes.com — B2600 GMC Code - Left Daytime Running Lamps Control Circuit

What does this mean?

What are the Possible Causes of the DTC B2600 GMC?

Faulty Left Headlamp Assembly
Left Headlamp Assembly harness is open or shorted
Left Headlamp Assembly circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B2600 GMC?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

B2600:01 Left Daytime Running Lamps Control Circuit short to Battery
B2600:02 Left Daytime Running Lamps Control Circuit Short to Ground
B2600:04 Left Daytime Running Lamps Control Circuit Open

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B2600 GMC code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the B2600 GMC code?

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Information for Specific GMC Models

B2600 2014 GMC Sierra — Left Daytime Running Lamps Control Circuit
B2600 2015 GMC Sierra — Left Daytime Running Lamps Control Circuit
B2600 2016 GMC Sierra — Left Daytime Running Lamps Control Circuit
B2600 2017 GMC Sierra — Left Daytime Running Lamps Control Circuit
B2600 2018 GMC Sierra — Left Daytime Running Lamps Control Circuit

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about B2600 GMC Code

1. What are the common symptoms of OBDII code B2600 related to the Left Daytime Running Lamps Control Circuit?

The common symptoms include the left daytime running lamp not functioning at all or flickering intermittently while driving.

2. What are the possible causes of OBDII code B2600 in a GMC vehicle?

Possible causes of code B2600 include a faulty left daytime running lamp bulb, a damaged wiring harness, a malfunctioning lamp control module, or a problem with the body control module.

3. How can I diagnose the issue causing OBDII code B2600 for the Left Daytime Running Lamps Control Circuit?

You can start by visually inspecting the left daytime running lamp for any visible damage or loose connections. Using a multimeter, you can also test the continuity of the wiring harness and check for any voltage irregularities.

4. What are some repair tips for resolving OBDII code B2600 in a GMC vehicle?

Try replacing the left daytime running lamp bulb first, as it is a common culprit for this code. If the issue persists, check and repair any damaged wires in the circuit, and consider testing or replacing the lamp control module or body control module if needed.

5. Can OBDII code B2600 cause any safety concerns while driving?

While the code itself does not pose an immediate safety risk, having a malfunctioning daytime running lamp can reduce visibility to other drivers, especially during low-light conditions or inclement weather. It is recommended to address the issue promptly for optimal safety on the road.

6. Is it possible to reset OBDII code B2600 without fixing the underlying issue?

Resetting the code without addressing the root cause will only temporarily clear the error code. The issue causing code B2600 will likely trigger the code again until properly diagnosed and repaired.

7. How do I clear OBDII code B2600 from the GMC's system after making the necessary repairs?

After fixing the underlying issue causing code B2600, you can clear the code using an OBDII scanner or by disconnecting the vehicle's battery for a few minutes to reset the system.

8. Are there any recalls or technical service bulletins related to OBDII code B2600 in GMC vehicles?

It is recommended to check with a GMC dealership or online databases for any recalls or technical service bulletins related to code B2600 in your specific GMC model and year to see if there are known issues or remedies provided by the manufacturer.

9. Can extreme weather conditions impact the triggering of OBDII code B2600 for the Left Daytime Running Lamps Control Circuit?

Extreme weather conditions, such as extreme cold or moisture, can potentially exacerbate issues with the left daytime running lamp circuit, leading to the triggering of code B2600. It is important to keep the vehicle well-maintained to prevent weather-related problems.

10. Is it possible to drive the GMC vehicle with OBDII code B2600 present?

While it is technically possible to drive the vehicle with code B2600 present, it is not recommended, as the malfunctioning left daytime running lamp can affect visibility and safety on the road. Addressing the issue promptly is advised.