2019-2020 Buick Envision Front Seat: Decoding Options and Solving Failures

Key Variants and Compatibility: The RPO Code Problem

Before buying a replacement front seat for a 2019-2020 Buick Envision, you must identify your vehicle's specific options. Mismatched features will result in functions that do not work. General Motors uses a system of three-character Regular Production Option (RPO) codes to identify the features installed on a vehicle from the factory. You can find these codes on a silver sticker, typically located inside the glove box.

Two of the most important RPO codes for Envision front seats are:

• KB6: This code signifies the vehicle is equipped with both heated AND cooled (ventilated) front seats. These seats have perforated leather and internal blower motors. A seat from a vehicle with only heated seats (RPO KA1) will not work correctly in a vehicle that came with the KB6 option.
• UHX: This code indicates the vehicle has Lane Keep Assist with Lane Departure Warning. Seats in vehicles with this option contain a haptic actuator (vibration motor) that provides a physical alert to the driver. If your Envision has UHX, your replacement seat must also come from a vehicle with this option for the safety alert feature to function.

Common Symptoms of Failure

Failures in the Envision's front seat are almost always electrical or mechanical, related to the various features they contain.

Power Seat Adjustments Not Working

If the seat won't move in one or all directions, the cause is often a faulty power seat switch on the side of the seat, a burned-out adjustment motor, or a wiring issue under the seat. Sometimes, debris can get stuck in the seat tracks, physically blocking movement. Check for a blown fuse first, as it's the simplest fix. If you hear a clicking sound when you press the switch but the seat doesn't move, the motor is likely receiving power but is unable to operate, pointing to an internal motor or gear failure.

Heated or Ventilated Seat Malfunctions

The most common symptom is the heater or ventilator not turning on. This is often caused by a broken heating element or a failed blower motor within the seat cushion or backrest. The thin wires in the heating element can break over time from occupant weight and movement. Other potential causes include a bad control switch, a faulty seat control module, or a blown fuse. In some cases, the seat may get too hot, which also indicates a fault in the control system.

Safety Alert Seat (Lane Keep Assist) Vibration Fails

If your Envision has the Lane Keep Assist system (RPO UHX) but you no longer feel the vibration in the seat cushion for lane departure warnings, the haptic actuator has likely failed. A "Service Driver Assist" message may also appear on the instrument cluster. GM issued a Technical Service Bulletin (TSB #20-NA-003) for this issue on 2016-2019 models, which involves replacing the actuators and reworking the harness polarity. This may also require reprogramming the seat memory control module.

Known Issues, Recalls, and Technical Service Bulletins (TSBs)

While the 2019-2020 Envision has not had major recalls specifically for the entire front seat assembly, there are related service communications and recalls for other model years that are relevant.

• TSB 20-NA-003: Addresses an inoperative front seat lane departure warning actuator (the vibration motor) and a "Service Driver Assist" message, which may be caused by incorrect wiring polarity from the factory. The fix involves replacing the actuators and swapping terminal positions in the connector.
• Recall 17V404 (Affects 2016-2017 models): Related to an improperly installed accessory tablet holder on the head restraints, which could prevent them from fully engaging in the seat back, increasing injury risk in a crash. While this doesn't apply directly to 2019-2020 models, it highlights the importance of ensuring headrests are properly seated.
• Customer Satisfaction Program N212354520 (Affects 2022-2023 models): Due to semiconductor shortages, many GM vehicles were built without functional heated/ventilated seats. A retrofit program was initiated to install the necessary modules later. This does not apply to the 2019-2020 model years but explains why some newer vehicles may have non-functional seat features.

Buying a Used 2019-2020 Envision Front Seat

Purchasing a used OEM seat is often the most cost-effective way to fix a major seat issue. Aftermarket full-seat replacements for modern vehicles like the Envision are virtually nonexistent due to the complexity of the integrated electronics and airbags. Here’s what to check.

Step 1: Verify RPO Codes and Features

This is the most critical step. Get the VIN from the donor vehicle and have the seller confirm the RPO codes, especially KB6 (heated/cooled) and UHX (Lane Keep Assist). Do not purchase a seat without confirming it has the exact same options as your original.

Step 2: Physical Inspection Checklist

• Upholstery: Check for rips, tears, burns, and deep stains in the leather or cloth. For ventilated seats (KB6), ensure the perforations are not clogged or torn.
• Plastic Trim: Inspect the side covers, switch bezels, and seat back panel for cracks, deep scuffs, or broken mounting clips. These pieces can be fragile.
• Wiring and Connectors: Look at the main harness connector under the seat. Ensure it is not cracked, and that no wires are cut, frayed, or show signs of corrosion. A damaged connector can cause endless electrical problems.
• Frame and Tracks: Examine the metal seat frame and mounting tracks for any signs of rust or deformation. A bent frame could indicate the seat came from a vehicle involved in a significant collision, which could compromise its structural integrity and the integrated airbag system.

Step 3: Test Functions (If Possible)

Ask the recycler if the seat's functions (power adjustments, heating, ventilation) were tested before it was removed from the donor vehicle. Reputable sellers will often test these components. If buying from a private party, it's best to see the seat operate in the vehicle before it's pulled.

Replacement Overview

Replacing the front seat is physically straightforward but requires careful handling of the electrical systems, particularly the airbag.

1. Disconnect the Battery: Disconnect the negative battery terminal and wait for the airbag system to discharge.
2. Unbolt the Seat: The seat is typically held to the floor by four bolts, one at each corner of the seat tracks. You may need to slide the seat forward and backward to access all of them.
3. Disconnect Wiring: Carefully tilt the seat backward to access the large electrical connector(s) underneath. Press the release tab and pull the connector apart. Do not pull on the wires themselves.
4. Remove the Seat: Lift the seat out of the vehicle. It is heavy and awkward, so a second person may be helpful to avoid scratching interior trim.
5. Installation: Installation is the reverse of removal. Ensure the main electrical connector is fully seated and clicks into place. Torque the seat bolts to the manufacturer's specification. Reconnect the battery last.

Frequently Asked Questions (FAQ)