2019-2025 Blazer Passenger Seat Heater Module: Programming, Diagnosis & Replacement

Symptoms of a Failing Seat Heater Control Module

When this module fails, the symptoms are usually straightforward. Because this specific module only controls the front passenger seat, a failure here will not affect the driver's side.

• Passenger Heated Seat Does Not Work: This is the most common symptom. The seat will not heat up on any setting, but the driver's side works fine.
• Heater Turns On, Then Immediately Off: You press the button, the indicator light comes on for a few seconds, and then it clicks off by itself. This is a common failure mode in many GM vehicles.
• Intermittent Operation: The seat heater works for a few minutes and then shuts off unexpectedly, or it may work on some trips but not others. This can point to failing internal electronics or a poor connection.
• Stuck on One Heat Level: The seat heats up, but you cannot change the temperature setting from low to high, or vice-versa.
• Burning Smell: A smell of burnt plastic or electronics from under the passenger seat is a critical warning sign. If you smell this, stop using the heated seat immediately to prevent a fire hazard.

Associated OBD-II Trouble Codes

A professional scan tool that can read Body Control Module (BCM) codes may find codes stored related to the seat heater system. Common codes include:

• B1925, B2170, B2425, B2430: These codes can indicate a fault in the seat heating control module circuit, often caused by a poor electrical connection at the module itself.
• B1921 - B1926: This range of codes points to malfunctions in the seat heater sensor or timer circuits.

Known Issues & Service Bulletins

While there are no direct safety recalls for this specific module on the 2019-2025 Blazer, GM has released related service information that is important for owners to know.

GM Customer Satisfaction Program N212354522

Due to the semiconductor shortage, some 2022 Chevrolet Blazer models were built and sold with the heated seat feature disabled. This program instructed dealers on how to retrofit the correct modules and enable the feature. Crucially, the procedure required dealers to install a new module and then reprogram the vehicle's Body Control Module (BCM) and/or HVAC Control Module to recognize and operate the new hardware. This bulletin confirms that the module is integrated with the vehicle's computer systems and requires programming to function.

Preliminary Information Bulletin PIT6239

For some 2025 Blazer EV models, owners may notice that the virtual buttons for the heated seats are missing from the infotainment screen. GM has identified this as a software anomaly and is working on a software update to fix it. This is not a module failure, but it shows how software can affect the system's operation.

Programming is Required After Installation

Yes, replacing this module requires programming. While some generic parts listings may state programming is not required, GM's own service procedures for modern vehicles like the Blazer show that programming is a mandatory step.

The module must be configured to your vehicle's specific Vehicle Identification Number (VIN) and options. Without programming, a new or used module will not communicate correctly with the Body Control Module (BCM), and the heated seat will not work. This is not a simple plug-and-play part.

• Who can program the module? A GM dealership is the most reliable option. Many professional independent repair shops that subscribe to GM's Service Programming System (SPS) can also perform the programming.
• Can I use a used module? Yes, a used OEM module is a good cost-saving option, but it must be reprogrammed for your vehicle's VIN after it is installed.

Buying a Used Seat Heater Control Module

A used OEM module can be a reliable and affordable alternative to a new part. Since these modules typically fail from electronic issues rather than physical wear, a part from a lower-mileage, accident-free vehicle is an excellent choice. Here's what to look for:

• Verify the Part Number: Match the part number on your original module exactly. The most common numbers for this application are 13527919 and 13531260. One may be a later revision or supersession of the other, but both are considered correct.
• Physical Inspection: Carefully inspect the connector pins. Look for any signs of green or white corrosion, bent pins, or melted plastic. The casing should be free of cracks or any signs of water intrusion.
• Source Vehicle Information: If possible, choose a part from a vehicle with known mileage and a clean history. Avoid parts from flood-damaged vehicles, as moisture is a primary cause of electronic failure.
• Remember the Programming Cost: Factor in the cost of programming when buying a used module. Call local shops or a dealer beforehand to get a quote for programming a customer-supplied part.

Cost of Replacement

The total cost will depend on the price of the part and local labor rates for installation and programming.

Frequently Asked Questions (FAQ)