AutoCodesGMC – B2665 GMC

B2665 GMC Code - Park Lamp Switch Circuit High

Quick Answer

The headlamp switch provides a ground input into the Body Control Module (BCM) for the park lamp switch input when the switch is activated. Common causes include Faulty Headlamp Switch, Headlamp Switch harness is open or shorted, Headlamp Switch 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
B2665 GMC indicates Park Lamp Switch Circuit High.
Common causes
Common causes include Faulty Headlamp Switch, Headlamp Switch harness is open or shorted, Headlamp Switch 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.
AI answers can be wrong. Verify repairs with testing. Open full chat
Code Popularity 539
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Jan 13, 2020
💬 Need more help? Ask Coddy for instant answers — it's free!

Code B2665 GMC Description

The headlamp switch provides a ground input into the Body Control Module (BCM) for the park lamp switch input when the switch is activated. This input is used by the BCM to control the park lamps. The Diagnostic Trouble Code (DTC) sets when the BCM detects a short to battery or open in the park lamp circuit when the Headlamp Switch is in the PARK position.
OBDII Code B2665 GMC - Park Lamp Switch Circuit High - AutoCodes.com
B2665 GMC Code - Park Lamp Switch Circuit High

What are the Possible Causes of the DTC B2665 GMC?

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

How to Fix the DTC B2665 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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B2665 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 B2665 GMC code?

Need more information on how to fix the B2665 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B2665 GMC code diagnosed by a professional: Find a repair shop in your area

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 B2665 GMC Code

1. What does the OBDII code B2665 mean on a GMC?

B2665 indicates a "Park Lamp Switch Circuit High," meaning the vehicle's control module has detected a high voltage issue in the park lamp switch circuit.

2. What are the symptoms of the B2665 code in a GMC vehicle?

Common symptoms include malfunctioning or non-operational park lamps, dashboard warning lights, or issues with exterior lighting at night.

3. What causes the B2665 code to appear on a GMC?

The code can be triggered by a faulty park lamp switch, damaged wiring, corroded connectors, or a malfunctioning body control module (BCM).

4. Can I drive my GMC with the B2665 code active?

While the vehicle may still function, driving with this issue could reduce visibility at night and create a safety hazard. It’s best to address the problem promptly.

5. How is the B2665 code diagnosed on a GMC?

A technician will inspect the park lamp switch, check for damaged or corroded wiring, and test the circuit voltage to ensure it is within the correct range.

6. Can I fix the B2665 code on my GMC myself?

If you are experienced with automotive electrical systems, you can check for loose connections or damaged wiring. However, more complex repairs may require professional assistance.

7. How much does it cost to repair the B2665 code on a GMC?

Repair costs can vary but typically range from $100 to $300, depending on the cause, such as replacing a switch, repairing wiring, or addressing BCM issues.

8. What tools are needed to diagnose the B2665 code?

Tools include a diagnostic scanner, a multimeter for voltage testing, and potentially wiring diagrams specific to your GMC model.

9. Can a blown fuse cause the B2665 code on a GMC?

While a blown fuse is not a typical cause of this code, it’s worth checking the fuse associated with the park lamp circuit as part of the diagnosis.

10. Does the B2665 code reset itself after repairs?

The code may reset after the issue is fixed, but in many cases, you’ll need to use an OBDII scanner to clear the code manually.

Discuss the causes and fixes for B2665 GMC OBDII Code

Code B2665 GMC comments

No comments found for this page.

AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play