2016-2022 Lexus RX350 & RX450h Power Liftgate: Fixing Grinding Noises and Beeping Failures

Symptoms of a Failing Power Liftgate Motor

When the power liftgate struts on a 2016-2022 Lexus RX350 or RX450h begin to fail, you'll notice very specific symptoms. Because these vehicles use two motorized struts, a problem with one can affect the entire system's operation.

• Grinding or Groaning Noises: A loud grinding, whirring, or groaning sound during operation is a classic sign of a failing electric motor or stripped internal gears within the strut assembly.
• Liftgate Stops Mid-Travel: The hatch may start to open or close, then stop partway and beep. This can happen if one motor is weaker than the other, causing the system to bind and trigger the obstruction sensor.
• Beeps and Reverses: A very common symptom is the liftgate lowering an inch or two, beeping twice, and then reversing back to the open position. The system interprets the failing strut's lack of smooth movement as an obstruction.
• A Single Long Beep: If you press a button and only hear a single, long beep with no movement, this indicates a general system malfunction. This could be the motor, but it can also point to a problem with the latch or a loss of system initialization.
• Hatch Won't Stay Open: If the liftgate opens but then slowly drifts down or won't stay fully open, the gas pressure inside the struts has failed. Even if the motor works, the strut can no longer support the weight of the door.
• Inoperative After Battery Change: The power liftgate system can lose its memory after the vehicle's battery is disconnected or replaced. It will remain inoperative, often with beeping alerts, until it is re-initialized.

Diagnosing the Problem: Is It the Motor, the Latch, or Just a Glitch?

Before spending money on parts, follow these diagnostic steps. Many liftgate issues on the RX350 and RX450h can be resolved with a simple reset.

1. Check the Glove Box Switch: Lexus vehicles have a master power liftgate switch in the glove compartment. Many owners have accidentally pressed this button, disabling the system. Ensure this button is in the 'ON' position (pressed in) before proceeding.
🎬 Watch: A quick guide on how to reset your liftgate.
2. Perform a System Initialization: If the system is acting erratically, especially after a dead battery, it needs to be reset. Manually push the liftgate to the fully open position. Then, press and hold the 'Close' button located on the bottom edge of the liftgate itself. Continue holding the button for about 5-10 seconds until you hear a series of beeps (typically 2 to 4). Release the button. Now try operating the liftgate normally.
3. Listen to the Sounds: If you hear grinding, the motor in one of the struts is the likely culprit. If you only hear beeps and clicks from the latch area, the problem may not be the lift motors.
4. Consider the Latch Assembly (2016-2017 Models): Lexus issued Technical Service Bulletin (TSB) L-SB-0137-17 for some 2016-2017 RX350 and RX450h vehicles. Symptoms include the hatch not unlatching, not closing fully, or stopping mid-operation, often with a long beep. This TSB points to a faulty power back door latch assembly, not the lift motors. This issue can set Body DTCs (Diagnostic Trouble Codes) B2250 or B2251, which require a more advanced scan tool to read.
🎬 See how to fix a latch that won't open or close.

Buying a Used Power Liftgate Motor

A used OEM power liftgate strut is an excellent, cost-effective alternative to an expensive new part. Because these units contain both mechanical and electronic components, buying a quality used OEM part is often more reliable than a cheap aftermarket alternative. Here’s what to look for:

• Verify the Part Number: Match the part number exactly, paying close attention to the left (68920-prefix) and right (68910-prefix) designations. See the full part number list below.
• Inspect for Physical Damage: Check the outer casing for cracks, dents, or signs of heavy impact. Ensure the electrical connector and wiring are intact with no cut or frayed wires.
• Check for Leaks: Inspect the strut shaft for any signs of oil residue. A leaking strut has lost its gas pressure and will not be able to support the weight of the hatch, even if the motor works.
• Mileage and Source Vehicle: Whenever possible, choose a part from a lower-mileage, accident-free vehicle. This increases the chances of the motor and gas strut having a long service life remaining.
• Why Used OEM is a Smart Choice: The original Lexus parts are designed to work perfectly with the vehicle's control systems. Aftermarket units can sometimes have slightly different operating speeds or power draws, which can confuse the control module and lead to the same binding or obstruction errors you're trying to fix.

Replacement Overview & Initialization

Replacing a power liftgate strut is a feasible DIY job for someone with intermediate mechanical skills. The process involves removing several interior trim panels in the cargo area to access the strut's upper mounting bolts and electrical connector. The lower end simply bolts to the liftgate itself.

Does the new motor need to be programmed?

No, a replacement power liftgate strut does not need to be programmed or flashed by a dealer using special software. However, it must be initialized to teach the system its new limits.

Initialization Procedure After Installation:

1. With the new strut installed, manually close the liftgate completely.
2. Press the liftgate open button on your dashboard or key fob. The system should now operate normally.
3. To set the opening height memory, manually move the gate to your desired height. Then, press and hold the 'Close' button on the liftgate until it beeps (about 2 beeps), confirming the position is stored.

If the system does not work after installation, you may need to perform a 'hard reset' by disconnecting the negative terminal of the vehicle's 12V battery for 10-15 minutes to clear any fault memory. Be aware this will also reset your radio presets and other vehicle settings.

Cost of Replacing a Power Liftgate Strut

Frequently Asked Questions (FAQ)

Technical Specifications and Part Numbers

OEM Part Numbers

Always confirm the part number and side before purchasing. Part numbers are often superseded, so multiple numbers may fit.