AutoCodes – GMC – B2622 GMC

B2622 GMC Code - Display Dimming Pulse Width Modulation Input Circuit

Quick Answer

The Body Control Module (BCM) receives a variable voltage signal from the Instrument Panel (I/P) Dimmer Switch requesting to illuminate the I/P controls illumination lamps to a desired intensity. Common causes include Faulty Instrument Panel (I/P) Dimmer Switch, Instrument Panel (I/P) Dimmer Switch harness is open or shorted, Instrument Panel (I/P) Dimmer 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: B2622 GMC indicates Display Dimming Pulse Width Modulation Input Circuit.
Common causes: Common causes include Faulty Instrument Panel (I/P) Dimmer Switch, Instrument Panel (I/P) Dimmer Switch harness is open or shorted, Instrument Panel (I/P) Dimmer 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.

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Code Popularity 1,116

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 Jan 09, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B2622 GMC Description

The Body Control Module (BCM) receives a variable voltage signal from the Instrument Panel (I/P) Dimmer Switch requesting to illuminate the I/P controls illumination lamps to a desired intensity. When this occurs, the BCM directly sends a variable voltage based on the I/P dimmer switch position through the I/P lamps supply voltage circuit to the I/P controls illumination lamps.

OBDII Code B2622 GMC - Display Dimming Pulse Width Modulation Input Circuit - AutoCodes.com — B2622 GMC Code - Display Dimming Pulse Width Modulation Input Circuit

What does this mean?

What are the Possible Causes of the DTC B2622 GMC?

Faulty Instrument Panel (I/P) Dimmer Switch
Instrument Panel (I/P) Dimmer Switch harness is open or shorted
Instrument Panel (I/P) Dimmer Switch circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B2622 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 B2622 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.

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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 B2622 GMC Code

1. What does the OBDII code B2622 mean on a GMC vehicle?

B2622 indicates an issue with the Display Dimming Pulse Width Modulation (PWM) Input Circuit, which controls the dimming of interior displays and lights.

2. What are common symptoms of the B2622 code?

Symptoms include non-functional or inconsistent dimming of interior displays, overly bright or dim dashboard lights, and possible flickering.

3. What causes the B2622 code to appear?

Common causes include a faulty dimmer switch, wiring issues such as open or shorted circuits, a malfunctioning Body Control Module (BCM), or a defective display panel.

4. Can I drive my GMC with the B2622 code?

Yes, the vehicle is typically still drivable, but the code may result in inconvenient lighting issues that could be distracting, especially at night.

5. How is the B2622 code diagnosed?

A technician will inspect the dimmer switch, wiring, and connectors for damage, use a scan tool to monitor the PWM signal, and check the BCM for faults.

6. How do you fix the B2622 code on a GMC vehicle?

Repairs may involve replacing the dimmer switch, repairing damaged wiring or connectors, reprogramming or replacing the BCM, or addressing any related electrical issues.

7. What tools are needed to troubleshoot the B2622 code?

A diagnostic scan tool, multimeter, and wiring diagrams for the vehicle are typically required to pinpoint the issue.

8. Is the B2622 code covered under warranty?

This depends on the vehicleâ€™s age, mileage, and warranty terms. Check with your dealership for specific coverage details.

9. Can a dead battery cause the B2622 code?

A low or dead battery can sometimes trigger electrical codes, including B2622, due to voltage irregularities affecting the dimming circuit.

10. How much does it cost to fix the B2622 code?

Repair costs vary depending on the specific issue but typically range from $100 to $500, depending on whether parts like the dimmer switch or BCM need replacement.