2015-2020 Acura TLX Parking Brake Module: Decoding Warnings and Programming Essentials
This guide explains the common 'Electric Parking Brake Problem' warning, details the required programming after replacement, and outlines the costs for your Acura TLX.
- The 'Electric Parking Brake Problem' light is often a false alarm triggered by a weak battery or an emissions system fault; diagnose these first.
- This module is NOT plug-and-play. It must be programmed to the vehicle using a dealer-level scan tool (like the Honda HDS) after installation.
- There are two different modules for the TLX. Match the part number to your engine: 39920-TZ3-A01 for the 3.5L V6 and 39920-TZ4-A01 for the 2.4L 4-cylinder.
- A truly failed module usually results in the parking brake being physically stuck, not just a warning light.
Known Issues & Important Warnings
Warning: The most common issue for TLX owners is an 'Electric Parking Brake Problem' message appearing on the dash, often at the same time as an 'Emissions System Problem' or other warning lights. In many cases, this does not mean the parking brake module has failed. This combination of warnings is frequently triggered by other, unrelated issues.
Before suspecting the module itself, investigate these common culprits first:
- Weak or Failing 12V Battery: Low system voltage during startup can cause multiple electronic modules to report errors simultaneously. This is the most frequent cause. If your battery is more than 3-4 years old, have it professionally tested before replacing any parts.
- Emissions System Faults: A faulty oxygen (O2) sensor or an EVAP system leak (like a loose gas cap or a leaking fuel filler neck) can, for reasons related to the car's complex software, trigger the parking brake warning light. Diagnostic Trouble Codes (DTCs) like P0456 (EVAP leak) are a major clue.
- Software Glitches: Sometimes, a temporary communication error between modules can cause the light to appear. In some cases, owners have reported the light disappearing on its own or after disconnecting the battery for a few minutes.
Recalls and Technical Service Bulletins (TSBs)
While there are no specific recalls for the parking brake control module on the 2015-2020 TLX, Acura has issued related documents. An internal investigation notice was sent to dealers regarding the 2015 TLX, where the EPB actuator (the motor on the caliper) would fail to release, sometimes setting codes like C1100, C1110, C1111, or C1120. Additionally, forum users frequently mention a TSB related to a leaking fuel filler neck that causes both emissions and parking brake warnings.
Symptoms of a Failed Parking Brake Module
If the module itself has failed, you will likely experience more than just a warning light. Look for these specific symptoms:
- Parking Brake is Stuck: The brake will not engage or, more critically, will not disengage, leaving the rear wheels locked. You may hear the motors trying to work, or there may be no sound at all.
- 'Electric Parking Brake Problem' Light (Without Other Warnings): If the EPB warning appears by itself, without any accompanying emissions or check engine lights, it is more likely to be a direct fault within the EPB system.
- Specific EPB Diagnostic Codes: A scan tool may show codes directly related to the module's internal logic or its communication, such as U0404-68 (Invalid Data Received From EPB Module).
Programming and Calibration Requirements
This is not a plug-and-play part. A replacement Parking Brake Control Module, whether new or used, must be programmed and calibrated to your specific vehicle.
The official Acura part name is 'EPB Unit (Rewritable)', which explicitly states that the module's software can be written to. This process requires a dealer-level diagnostic tool, such as the Honda Diagnostic System (HDS). A generic OBD-II code reader cannot perform this function. The procedure involves initializing the new module, teaching it the vehicle's parameters, and calibrating the brake caliper motors.
Even a simple rear brake pad replacement on a TLX requires a scan tool to put the system into a special 'Brake Pad Maintenance Mode' to retract the caliper pistons. This demonstrates the level of integration and the necessity of proper tools for any service related to the EPB system. Failure to program a new module will result in it not working and a persistent warning light on the dashboard.
Buying a Used Parking Brake Control Module
A used OEM module is an excellent, cost-effective alternative to a new part, especially since new aftermarket options are not readily available. Follow these guidelines for a successful purchase:
- Match the Part Number to Your Engine: This is the most important step. The 2015-2020 TLX uses two different modules depending on the engine. Verify the part number on your original module before buying.
- 3.5L V6 Models: Use part number 39920-TZ3-A01.
- 2.4L 4-Cylinder Models: Use part number 39920-TZ4-A01.
- Inspect for Damage: Check the replacement module for any physical damage, especially to the plastic housing and the connector pins. The module is located in the driver's side of the trunk, behind the liner, so it is generally protected from weather but can be damaged by impacts or loose cargo.
- Budget for Programming: Remember to factor in the cost of having an Acura dealership or a qualified independent shop with an HDS tool program the used module to your car. This is a mandatory step.
Cost to Replace the Parking Brake Control Module
The total replacement cost includes the part itself, labor for installation, and the necessary programming.
| Item | Estimated Cost |
|---|---|
| New OEM Module | $300 - $455 |
| Used OEM Module | $75 - $170 |
| Shop Labor (Installation & Programming) | $150 - $300 |
| Total Estimated Cost (Used OEM) | $225 - $470 |
| Total Estimated Cost (New OEM) | $450 - $755 |
Labor costs are estimates and will vary by location and shop.
Frequently Asked Questions (FAQ)
Does a used 2015-2020 TLX parking brake module need to be programmed?
Yes, absolutely. The module is listed as 'Rewritable' by Acura and must be electronically paired with your vehicle's computer system using a dealer-level scan tool. It will not function correctly if you simply swap it in.
Why did my 'Electric Parking Brake Problem' and 'Emissions System Problem' lights come on together?
This is a common software quirk in many modern Acuras and Hondas. The EPB system is sensitive to low voltage or faults in other systems. A weak battery, a bad O2 sensor, or an EVAP leak are the most common triggers for this combination of warnings. Always diagnose the emissions code or test the battery first.
Can I replace the parking brake module myself?
While the physical replacement is straightforward for a DIY mechanic (it's located behind the trunk liner on the driver's side), the final programming step makes this a difficult DIY job. Unless you have access to a professional Honda/Acura HDS scan tool, you will need to have the vehicle towed to a shop for the final, critical step.
Where is the parking brake control module located on a 2015-2020 Acura TLX?
The module is located in the trunk. You can access it by removing the trunk floor and pulling back the carpeted liner on the driver's side (left side) of the vehicle. It is a black plastic box with electrical connectors.
Technical Specifications
OEM Part Numbers: 39920-TZ3-A01 (For 3.5L V6 Models) 39920-TZ4-A01 (For 2.4L L4 Models)
Location: Driver's side of trunk, behind liner. Requires programming with Honda Diagnostic System (HDS) or equivalent scan tool.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Acura TLX:
- 🛍️ Shop This Part
- Known Issues & Important Warnings
- Recalls and Technical Service Bulletins (TSBs)
- Symptoms of a Failed Parking Brake Module
- Programming and Calibration Requirements
- Buying a Used Parking Brake Control Module
- Cost to Replace the Parking Brake Control Module
- Frequently Asked Questions (FAQ)
- 🎟️ Get 5% Off