AutoCodes – GMC – B2238 GMC

B2238 GMC Code - Left Door Un-Lock Switch Fault

Quick Answer

The driver or passenger door switch signal circuits provide inputs to the Driver Door Module (DDM) or Passenger Door Module (PDM) when a door lock switch is activated to the LOCK or UNLOCK position. Common causes include Faulty Left Door lock Switch, Left Door lock Switch harness is open or shorted, Left Door lock 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: B2238 GMC indicates Left Door Un-Lock Switch Fault.
Common causes: Common causes include Faulty Left Door lock Switch, Left Door lock Switch harness is open or shorted, Left Door lock 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 566

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 Oct 10, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B2238 GMC Description

The driver or passenger door switch signal circuits provide inputs to the Driver Door Module (DDM) or Passenger Door Module (PDM) when a door lock switch is activated to the LOCK or UNLOCK position. These inputs allow the door module to detect a door LOCK or UNLOCK request. The door modules provide power and ground to the door lock switches. When a door lock switch is activated to the LOCK or UNLOCK position, ground is supplied through the door lock switch to the signal circuit, which is pulled low. When the door module detects low voltage on the signal circuit, it will command the door latches to LOCK or UNLOCK. If the driver door switch is activated, the DDM will LOCK or UNLOCK the driver door latch and also send a message on the serial data line to the PDM to LOCK or UNLOCK the passenger door latch. If the passenger door switch is activated, the PDM will LOCK or UNLOCK the passenger door latch and also send a message on the serial data line to the DDM to LOCK or UNLOCK the driver door latch. The door modules monitor the signal circuits to determine how long the ground has been applied. If the door module detects that a ground is applied for greater than 20 seconds, a Diagnostic Trouble Code (DTC) is set.

OBDII Code B2238 GMC - Left Door Un-Lock Switch Fault - AutoCodes.com — B2238 GMC Code - Left Door Un-Lock Switch Fault

What does this mean?

What are the Possible Causes of the DTC B2238 GMC?

Faulty Left Door lock Switch
Left Door lock Switch harness is open or shorted
Left Door lock Switch circuit poor electrical connection
Faulty Driver Door Module (DDM)

How to Fix the DTC B2238 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 B2238 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 B2238 GMC Code

1. What does the OBDII code B2238 mean for GMC vehicles?

B2238 indicates a fault with the left door unlock switch, typically caused by electrical or mechanical issues preventing proper operation.

2. What are the common symptoms of a B2238 code?

Symptoms may include the left door not unlocking, intermittent functionality of the unlock switch, or unresponsive door lock controls.

3. What can cause the B2238 code to appear?

The code can be triggered by a faulty unlock switch, damaged wiring, poor electrical connections, or issues with the door module.

4. Can a blown fuse cause the B2238 code?

Yes, a blown fuse related to the door lock circuit can disrupt power to the unlock switch and cause this code.

5. How can I diagnose the B2238 code?

Start by inspecting the left door unlock switch, checking the wiring and connectors for damage, and testing continuity to ensure proper electrical flow.

6. Is the B2238 code related to the door lock actuator?

It can be, as a malfunctioning actuator may prevent the unlock switch from working correctly, particularly if the actuator is not receiving signals.

7. How do I fix the B2238 code on a GMC vehicle?

Repair or replace the left door unlock switch, inspect and repair wiring or connectors, and ensure the door lock actuator is functioning properly.

8. Can the B2238 code cause other door lock issues?

It typically affects the left door unlock function but may cause intermittent issues with the overall door lock system if wiring or module problems are involved.

9. Will clearing the B2238 code solve the problem?

Clearing the code without addressing the underlying issue will likely result in the code reappearing.

10. Is professional assistance required to fix the B2238 code?

While some issues like a faulty switch or damaged wiring can be fixed at home, complex electrical problems may require professional diagnosis and repair.