OEM Differential Control Module for 2018-2025 Buick, Cadillac, Chevrolet, & GMC

What to Look For:

• Ensure the part is the correct type for your vehicle's specific year, make, and model.
• Check for any visible signs of damage, such as cracks, dents, or corrosion.
• If buying a used part, inquire about its history and previous usage.

Quality Indicators:

• For used OEM parts, look for components that have been thoroughly tested and inspected.
• Check if the used OEM part comes with a warranty.
• For new aftermarket parts, research the manufacturer's reputation and quality control standards.

What's Included:

• Typically, you'll receive only the Differential Control Module itself.
• Mounting hardware and instructions are usually not included.
• Verify exactly what is included with the seller before purchase.

Difficulty Level and Estimated Time:

• Difficulty: Intermediate
• Estimated Time: 1-2 hours

Special Tools Needed:

• Basic hand tools (sockets, wrenches, screwdrivers)
• OBD-II scanner for clearing diagnostic trouble codes
• Multimeter (optional, for testing power and ground)

Critical Steps and Tips:

1. Disconnect the negative battery cable before starting any electrical work.
2. Locate the Differential Control Module. It's typically mounted near the rear differential.
3. Disconnect the wiring harness from the module.
4. Remove the mounting bolts and carefully remove the old module.
5. Install the new module in the reverse order.
6. Reconnect the wiring harness and the negative battery cable.
7. Clear any diagnostic trouble codes using an OBD-II scanner.

DIY or Professional Installation:

• DIY is possible for mechanically inclined individuals with some electrical knowledge.
• Professional installation is recommended if you're not comfortable working with electrical systems or if you lack the necessary tools.

Compare: Used OEM, New Aftermarket

Used OEM:

Used OEM Differential Control Modules offer a cost-effective solution. These are genuine factory parts that have been removed from vehicles. They are typically tested and inspected to ensure they are in good working condition. You get the quality of an OEM part at a significantly lower price.

New Aftermarket:

New aftermarket Differential Control Modules are manufactured by third-party companies. They are designed to meet or exceed the original equipment specifications. These parts are brand new and offer a potentially longer lifespan compared to used parts.

Parts Commonly Replaced or Checked:

• Differential fluid
• Wiring harness connectors
• Wheel speed sensors
• Four-wheel drive switch

Preventing Repeat Failures:

Replacing related parts can help prevent repeat failures by addressing underlying issues that may have contributed to the original problem. For example, replacing the differential fluid can ensure proper lubrication and prevent overheating. Checking the wiring harness connectors can identify and correct any corrosion or loose connections.

How Long This Part Normally Lasts:

• A Differential Control Module can last for 100,000 miles or more under normal driving conditions.

Factors That Affect Longevity:

• Driving habits (aggressive off-roading can shorten lifespan)
• Environmental conditions (exposure to water, salt, and extreme temperatures)
• Maintenance (proper differential fluid changes)
• Electrical system health (voltage spikes or shorts can damage the module)

Budget vs Mid-Range vs Premium Options:

• Used OEM: $100 - $300
• New Aftermarket: $200 - $500

Labor Cost Considerations:

• Professional installation labor costs can range from $100 to $300, depending on the mechanic's hourly rate and the complexity of the job.

Total Job Cost Estimates:

• DIY with Used OEM: $100 - $300 (part only)
• DIY with New Aftermarket: $200 - $500 (part only)
• Professional Installation with Used OEM: $200 - $600 (part and labor)
• Professional Installation with New Aftermarket: $300 - $800 (part and labor)

Known Issues:

Some models within the specified year range have experienced issues with water intrusion into the Differential Control Module due to faulty seals. This can lead to corrosion and premature failure.

TSBs or Common Complaints:

Check for any Technical Service Bulletins (TSBs) related to the Differential Control Module on your specific vehicle model. These bulletins may provide valuable information about known issues and recommended solutions. Also, research common complaints on online forums specific to your vehicle.

How to Confirm Proper Operation:

• Start the vehicle and engage four-wheel drive.
• Verify that the four-wheel drive system engages smoothly and without any unusual noises.
• Drive the vehicle in four-wheel drive and ensure that it provides adequate traction.
• Use an OBD-II scanner to check for any new diagnostic trouble codes.

What to Look/Listen For:

• Smooth engagement and disengagement of four-wheel drive
• No unusual noises from the rear differential
• Proper traction in four-wheel drive
• No warning lights on the dashboard

Q: Will this Differential Control Module fit my vehicle?
A: While this module fits a range of Buick, Cadillac, Chevrolet, and GMC vehicles from 2017-2025, it's critical to verify compatibility based on your vehicle's specific year, make, and model.

Q: Do I need to program this Differential Control Module after installation?
A: In some cases, programming may be required for the module to communicate properly with your vehicle's computer system. Consult your vehicle's repair manual or a qualified mechanic to determine if programming is necessary.

Q: What is the difference between a used OEM and a new aftermarket Differential Control Module?
A: A used OEM module is a genuine factory part that has been removed from a vehicle. A new aftermarket module is manufactured by a third-party company. Used OEM modules are typically less expensive, while new aftermarket modules offer a potentially longer lifespan.

Q: How can I tell if my Differential Control Module is the problem?
A: Common symptoms include a service AWD or 4WD light, difficulty shifting into or out of four-wheel drive, unusual noises from the rear differential, and a loss of four-wheel drive functionality. It's best to have a qualified mechanic diagnose the problem to confirm the Differential Control Module is the cause.

Q: Does this part come with a warranty?
A: Warranty coverage varies depending on the seller and whether you purchase a used OEM or new aftermarket part. Check the seller's warranty policy before making a purchase.

OEM Part Numbers:

• GM: 40181635, 40197852, 40248369, 84207916, 8424501, 84245017, 84245195, 84311135, 84356899, 84440525, 84456686, 84463612, 84849877, 85001638

Fits Years: 2018 2019 2020 2021 2022 2023 2024 2025