2016 Lexus GS F Power Steering Module: Failure, Programming, and Replacement

Symptoms of a Failing Power Steering Control Module

A problem with the Power Steering Control Module in a 2016 Lexus GS F will be immediately noticeable. The most common signs point to a partial or complete loss of steering assist.

• Sudden Heavy Steering: The most prominent symptom is a sudden loss of power assist, making the steering wheel extremely difficult to turn, especially at low speeds. This can feel like the car has stalled, even though the engine is still running.
• Power Steering (P/S) Warning Light: An amber "P/S" warning light will illuminate on the dashboard, indicating a fault within the Electric Power Steering system.
• Multiple Warning Lights: A failing module can disrupt communication with other vehicle systems. It's common to see a cascade of warning lights, including "Check VSC," "Check ABS," and "Check DRS."
• Intermittent Failure: In some cases, the failure may be intermittent. A restart of the vehicle might temporarily restore function, but the underlying problem remains. This can sometimes be triggered by voltage fluctuations from an aging battery or alternator.

Associated OBD-II Trouble Codes

A professional scan tool is required to read codes from the power steering system. Common codes associated with Lexus EPS failures include:

• U0131: Lost Communication With Power Steering Control Module. This is a strong indicator that the module is failing or has a connection issue.
• C1515 / C1525: Torque Sensor Zero Point Adjustment Undone / Rotation Angle Sensor Initialization Undone. These codes indicate a calibration issue, which can occur after a module replacement if not programmed correctly.
• C1555: Motor Relay Welding Failure. This points to an internal failure within the power steering ECU itself.

Known Issues, TSBs, and Recalls

As of mid-2026, there are no specific recalls or Technical Service Bulletins (TSBs) from Lexus for the power steering control module on the 2016 GS F. A recall existed for a fuel pump issue on this model, but it is unrelated to the steering system. The lack of specific bulletins is likely due to the low production volume of the GS F model. Most known issues are derived from owner experiences and data from similar Lexus models of the same era.

Buying a Used Power Steering Control Module

Given the high cost of a new module, a used OEM unit from a reputable automotive recycler is a smart financial choice. However, there are critical factors to consider.

1. Match the Part Number Exactly: The only way to ensure compatibility is to match the OEM part number precisely. For the 2016 Lexus GS F, the correct part number is 89650-30E00. Do not use a module from a GS 350 or other Lexus model, even if it looks identical, as the internal programming for the GS F's specific steering and suspension setup (like VGRS) is different.
2. Physical Inspection: When you receive the used module, inspect it carefully. Look for any signs of corrosion on the connector pins, water damage to the case, or physical damage from the donor vehicle. The module should be clean and free of any obvious defects.
3. Factor in Programming Costs: A used module is not a plug-and-play part. It will require professional programming to function in your vehicle. You must account for this additional cost, which typically involves about an hour of shop labor.
4. Source from a Reputable Seller: Purchase from a seller that offers a warranty. This protects you in the rare event that you receive a defective part.

Replacement and Programming Guide

Replacing the module is mechanically straightforward, but the required electronic calibration makes this a job best left to a professional technician or an experienced DIYer with access to the right tools.

Part Location

The Power Steering Control Module is located in the engine bay on the passenger (right-hand) side. It is situated underneath the vehicle's 12V battery and the plastic battery tray.

Replacement Steps

1. Disconnect the negative battery terminal and wait at least 90 seconds for the vehicle's systems to power down.
2. Remove the battery hold-down, then remove the battery itself.
3. Unclip and remove the plastic battery tray to expose the Power Steering Control Module underneath.
4. Disconnect the electrical connectors from the module.
5. Unbolt the module from its mounting bracket (typically three bolts).
6. Install the new or used module, reconnect the electrical connectors, and reinstall the battery tray and battery.

Required Programming: Zero Point Calibration

After installation, the module must be calibrated to the vehicle's sensors. This process is known as "Zero Point Calibration." It synchronizes the steering angle sensor and torque sensor with the module, ensuring the system knows the straight-ahead position of the wheels. Without this step, the power steering will not work, and multiple warning lights will remain on.

This calibration must be performed using Toyota/Lexus's proprietary Techstream diagnostic software. While some online guides show a method using a paperclip to jump pins on the OBD-II port, the Techstream method is the official and most reliable procedure.

The Techstream process generally involves:

1. Connecting the Techstream tool to the vehicle's OBD-II port.
2. Navigating to the 'Chassis' system, then 'EMPS' (Electric Motor Power Steering) or 'ABS/VSC/TRAC'.
3. Selecting the 'Utility' menu.
4. Choosing 'Reset Memory' and/or 'Test Mode' to perform the calibration. The on-screen prompts will guide the technician through the process, which may involve keeping the steering wheel centered.

A Lexus dealer or a qualified independent shop that specializes in Toyota/Lexus vehicles will have this software and can perform the calibration. Expect to pay for about one hour of labor for this service.

Cost Comparison

The cost to replace the Power Steering Control Module can vary significantly based on the source of the part.

Frequently Asked Questions