2017-2023 Chevrolet Bolt EV Rear Window Regulator: Failure, Diagnosis, and Replacement

Symptoms of a Failing Rear Window Regulator

When a window regulator starts to fail in a Bolt EV, the signs are usually obvious. Being aware of these symptoms can help you diagnose the problem before the window gets stuck completely.

• Grinding, Clicking, or Popping Noises: The most common symptom is a grinding or clicking sound when operating the window. This is often caused by the internal steel cable fraying, binding, or a plastic pulley breaking.
• Slow or Erratic Window Movement: If the window moves noticeably slower than it used to, or if it stutters on its way up or down, it can indicate a failing motor or increased resistance from a damaged regulator.
• Window Drops Inside the Door: In cases of complete failure, the cable can snap or the glass clamps can break, causing the window to fall completely inside the door.
• Crooked Window: If the window appears tilted or doesn't seal correctly when closed, it means the regulator's support mechanism is bent or broken, preventing the glass from moving evenly.
• Window Won't Move, But Motor Hums: If you can hear the motor trying to work when you press the switch but the window doesn't move, the regulator's cable is likely jammed or broken.
• Window Doesn't Move, No Sound: If there's no sound from the motor, the issue could be the motor itself, the switch, or a fuse. However, since the regulator and motor are typically replaced as an assembly, the diagnosis often leads to the same part.

Known Issues, TSBs, and Recalls

While there are no recalls specifically for the window regulator on the 2017-2023 Bolt EV, there are some related items and a Technical Service Bulletin (TSB) for the front windows that indicate potential issues with the cable design.

• NHTSA Recall A202298320: This recall affects some 2019-2020 Bolt EV models. It addresses an issue where an overly long rear door handle cable could be damaged by the window when it's rolled down. This could cause the rear door to open unexpectedly. While not a regulator failure, the repair involves accessing the same area inside the door.
• TSB 17-NA-277: This bulletin was issued for 2017 Bolt EV models regarding the front window regulator cables fraying or breaking. While it doesn't officially cover the rear windows, it suggests that cable durability can be a weak point in the vehicle's window regulator design.

Buying a Used 2017-2023 Bolt EV Rear Window Regulator

Purchasing a used OEM window regulator can be a cost-effective solution, as these parts are generally reliable and do not have a high failure rate. Here’s what to check before you buy:

1. Verify Compatibility: Double-check that the part is from a Bolt EV, not a Bolt EUV. Confirm the part number and which door it fits (rear driver side vs. rear passenger side).
2. Inspect the Cables: Look closely at the steel cables. They should be tightly wound around the pulleys and drum. Avoid any regulators with visible fraying, kinks, or rust. A frayed cable is the most common point of failure.
3. Check Plastic Components: Examine the plastic pulleys and the glass carrier clips. Ensure they are not cracked, brittle, or broken. These plastic parts can become brittle over time.
4. Examine the Motor: Check the electrical connector on the motor for any signs of corrosion or damage. The motor is included with the regulator assembly, so you are getting both parts.
5. Mileage Isn't a Major Factor: Unlike engine or transmission components, window regulator life is more dependent on use cycles than mileage. A part from a low-mileage car is generally better, but a high-mileage part can still have plenty of life left if the windows weren't used excessively.

Cost of Replacement

The cost to replace a rear window regulator can vary significantly based on the part source and who performs the labor.

Replacement Guide & Programming

Replacing the rear window regulator is a manageable DIY job for someone with basic mechanical skills. The process involves removing the door panel, peeling back the vapor barrier, unbolting the old regulator, and installing the new one.

Difficulty: 2.5 out of 5
Estimated Time: 1-1.5 hours

Window Programming (Normalization)

After replacing the regulator or disconnecting the battery, the window's "express-up/down" feature may not work. You will need to normalize or "relearn" the window's position. This is a simple procedure that does not require special tools.

1. Close the car door.
2. Turn the vehicle on.
3. Press and hold the window switch down until the window is fully open. Continue holding the switch for 5 seconds.
4. Pull and hold the window switch up until the window is fully closed. Continue holding the switch for 5 seconds.
5. The express-up/down function should now be restored. If it doesn't work, repeat the process.

Part Number and Compatibility Guide

Note: Part numbers can be superseded. Always verify fitment with the seller using your vehicle's VIN. The part for the Bolt EUV is different.

Frequently Asked Questions (FAQ)