2018-2022 Regal & Insignia Seat Control Module: Fixing Failed Heated & Ventilated Seats

Is This a Body Control Module (BCM) or a Seat Control Module?

It's important to clarify that while this part is an electronic control module, it is not the main Body Control Module (BCM) of the vehicle. This specific part, identified by GM part numbers 13518170 and 13523745, is a Seat Control Module. The main BCM manages systems like power windows, door locks, and lighting for the entire car. This module's only job is to control the functions of a single front power seat, including its movement, memory settings, and heating/ventilation features. This guide is specific to the Seat Control Module for the 2018-2020 Buick Regal (Sportback and TourX models) and its European counterpart, the 2018-2022 Opel Insignia, which are built on the same platform and share these components.

Symptoms of a Failing Seat Control Module

When the seat control module begins to fail, you will notice problems with the power seat functions. Here are the most common symptoms:

• Heated and/or Ventilated Seat Inoperative: The heating or cooling function for one of the front seats stops working entirely or works intermittently. This is one of the most common signs of a failing module.
🎬 Watch this diagnostic video on a Buick Regal seat heater failure.
• Power Seat Adjustments Don't Work: The seat may become stuck in one position, or some adjustments (like forward/back or recline) will stop working while others still function.
• Seat Memory Function Fails: The module loses its ability to save or recall stored seating positions. You might press the memory button and nothing happens.
• Intermittent Operation: The seat functions may work one day and not the next, or require multiple button presses to respond. This can point to internal corrosion or failing electronic components.
• Clicking Noises Without Movement: You might hear a click from under the seat when you press an adjustment button, but the seat motor doesn't engage.
• Burning Smell: In rare but serious cases, a failing module can overheat, producing a burnt plastic or electrical smell. If you notice this, stop using the seat functions immediately.

A technician can use a diagnostic scan tool to check for specific trouble codes. Common codes related to a faulty seat module include:

• B2300: Driver Seat Memory Error
• B3920 / B3921: Power Seat Motor Circuit Malfunction (on GM vehicles)
• U0208 / U0562: Lost Communication With Seat Control Module
• Various B-codes related to seat heater circuits (e.g., B1921-B1925)

Known Issues, TSBs, and Recalls

While there are no specific recalls for this seat control module on the 2018-2020 Buick Regal or Opel Insignia, several related recalls and issues are worth noting:

• NHTSA Campaign #19V762000: Affects 2019-2020 Buick Regals for an improperly welded lower crossbar on the seat frame. While not an electronic issue, it involves the seat structure.
• NHTSA Campaign #22V465000: A software error in the Electronic Brake Control Module (EBCM) could affect power brake assist in 2018-2020 Buick Regals. This is unrelated to the seat module but is an important electronic issue for these vehicles.
• Water Intrusion: Like any electronic module located under a seat, this part is vulnerable to damage from moisture. Spilled drinks or water tracked into the vehicle can seep into the module's casing and corrode the circuit board, leading to failure.

Programming and Installation Requirements

For General Motors vehicles of this era, including the Buick Regal and its Opel counterpart, replacing an electronic module like this requires programming. This process uses special software to configure the new module to your vehicle's specific Vehicle Identification Number (VIN) and its factory options.

• What does programming do? Programming allows the new seat module to communicate with the vehicle's other computers over the data network (CAN bus). It ensures that all functions you paid for—like memory, heating, and ventilation—are enabled and work correctly. Without programming, the module may not function at all, or only basic adjustments will work.
• Who can program it? A GM dealership is the most reliable option. They use the official GM Techline Connect software and Service Programming System (SPS). Many well-equipped independent repair shops that specialize in GM vehicles also have the necessary J2534 pass-thru tools and software subscriptions to perform this programming. A typical DIY mechanic or small local shop will not have this capability.
• Is there an anti-theft link? No, the seat control module is not tied to the vehicle's immobilizer system. Programming is for configuration and communication, not for anti-theft security.

Buying a Used Seat Control Module

A used OEM module is an excellent, cost-effective alternative to a brand-new part, provided you take a few precautions. Since this is an electronic component, careful inspection is key.

1. Match the Part Number EXACTLY: This is the most important rule. Your replacement module must have the exact same OEM part number as your original. The primary part number is 13523745, which replaces the older number 13518170. Check the sticker on your original module and buy one that matches.
2. Verify Vehicle Options: The initial data for this part specifies it is for seats with both heating and ventilation. A module from a vehicle with only heated seats or basic power functions will not operate the ventilation feature correctly.
3. Inspect for Corrosion and Water Damage: Carefully examine the electrical connector pins for any signs of green or white corrosion. Look at the plastic casing for any water stains or cracks. Do not buy a module that looks like it has been wet.
4. Buy from a Reputable Source: Purchase from a seller that offers a warranty and has good reviews. This gives you protection in case you receive a defective part. An eBay listing for a used module from a 2018 Regal with 60k miles shows what a good used part should look like.

Cost Breakdown

The cost to replace a seat control module includes the part itself and the labor for installation and programming. Here is an estimated breakdown:

Note: Prices are estimates as of late 2024 and can vary based on location and supplier. Interestingly, new OEM modules are currently very inexpensive, making them a viable option over used parts.

Frequently Asked Questions (FAQ)