AutoCodes – GMC – B2605 GMC

B2605 GMC Code - Right Daytime Running Lamps Control Circuit

Quick Answer

The ambient light sensor is used to monitor outside lighting conditions. Common causes include Faulty Right Headlamp Assembly, Right Headlamp Assembly harness is open or shorted, Right 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: B2605 GMC indicates Right Daytime Running Lamps Control Circuit.
Common causes: Common causes include Faulty Right Headlamp Assembly, Right Headlamp Assembly harness is open or shorted, Right 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 980

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 B2605 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 B2605 GMC - Right Daytime Running Lamps Control Circuit - AutoCodes.com — B2605 GMC Code - Right Daytime Running Lamps Control Circuit

What does this mean?

What are the Possible Causes of the DTC B2605 GMC?

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

How to Fix the DTC B2605 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

B2605:01 Right Daytime Running Lamps Control Circuit short to Battery
B2605:02 Right Daytime Running Lamps Control Circuit Short to Ground
B2605:04 Right Daytime Running Lamps Control Circuit Open

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B2605 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 B2605 GMC code?

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Need Help with the Code?

Get the B2605 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

B2605 2014 GMC Sierra — Right Daytime Running Lamps Control Circuit
B2605 2015 GMC Sierra — Right Daytime Running Lamps Control Circuit
B2605 2016 GMC Sierra — Right Daytime Running Lamps Control Circuit
B2605 2017 GMC Sierra — Right Daytime Running Lamps Control Circuit
B2605 2018 GMC Sierra — Right 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 B2605 GMC Code

1. What does the OBDII code B2605 mean on a GMC vehicle?

The code B2605 indicates a fault in the Right Daytime Running Lamps (DRL) Control Circuit, typically caused by a wiring or component issue.

2. What are the common symptoms of code B2605 in a GMC?

Symptoms include the right daytime running lamp not functioning, a dashboard warning light, or both.

3. What causes the B2605 code to appear in GMC vehicles?

Common causes include a burned-out bulb, damaged wiring, a faulty DRL control module, or a poor electrical connection.

4. How can I diagnose the B2605 code on my GMC?

Inspect the right DRL bulb, wiring, and connectors for damage. Use a multimeter to check for continuity and proper voltage in the circuit.

5. Can a blown bulb trigger the B2605 code on a GMC?

Yes, a blown right DRL bulb is one of the most common reasons for this code.

6. How do I fix the B2605 code on a GMC vehicle?

Replace the right DRL bulb if itâ€™s burned out, repair any damaged wiring, and ensure all connections are secure. Replace the control module if necessary.

7. Is it safe to drive with the B2605 code on a GMC?

While the vehicle is generally safe to drive, you may face reduced visibility for other drivers due to the non-functioning DRL.

8. Can a bad DRL control module cause the B2605 code in a GMC?

Yes, a faulty DRL control module can lead to this code by failing to properly regulate the circuit.

9. How much does it cost to fix the B2605 code on a GMC?

Costs vary depending on the issue, but replacing a bulb is inexpensive, while repairing wiring or replacing a control module can be more costly, ranging from $50 to $300.

10. Can a DIY approach fix the B2605 code on a GMC?

Yes, if youâ€™re comfortable checking and replacing bulbs or inspecting wiring, you can often resolve this code without professional help.