Where is the ECU on a Acura TSX?
The Engine Control Unit (ECU) on a typical Acura TSX is mounted in the engine compartment, on the passenger side near the firewall. It’s a rectangular module connected to the main wiring harness and usually protected by a plastic cover.
Location in the engine bay
For most TSX models produced between 2004 and 2014, the ECU (often referred to as the ECM in Honda/Acura terminology) sits in the engine compartment on the passenger side, close to the firewall. It’s typically attached to a bracket or the inner fender and shielded by a removable plastic cover to protect the connectors.
Before you begin inspecting, ensure the vehicle is off and the negative battery terminal is disconnected if you intend to work around electrical connections. The ECU is a rectangular box with multiple wiring harness connectors on its side.
- Open the hood and look toward the passenger side of the engine bay near the firewall for a box-like module with a multi-pin connector entering the side.
- Check around the strut tower area or where the inner fender bracket is located; the ECU is usually mounted on that side with a bracket.
- Remove any protective covers or shields that hide the module to access the connectors and mounting bolts.
Once you locate it, you’ll see several large connectors and a label indicating part numbers and ratings. The unit is designed to be accessible for diagnostics and replacement without removing major engine components.
Year variations and naming
While the engine bay location is standard for most Acura TSX models, some years or trims may vary slightly in how the ECU is mounted or shielded. The term ECM (engine control module) is commonly used interchangeably with ECU in these vehicles. If you’re unsure, consulting the owner’s manual or a service manual for your exact year and trim will confirm the precise mounting arrangement.
What to do if you can’t locate it in the engine bay
In rare cases or with dealer modifications, an ECM can be relocated. If the unit isn’t visible in the engine bay, reference the vehicle’s service documentation or contact a dealer to confirm the correct location for your specific year/model. In many cases, the ECM still resides in the engine compartment, but some alternative installations or aftermarket work can place it elsewhere.
Safety and handling considerations
Working with the ECU involves electrical risk and the potential for short circuits. Always disconnect the battery before inspecting or disconnecting connectors, work in a dry environment, and handle connectors and harnesses with care to avoid static discharge or bent pins. If you’re replacing or reprogramming the ECU, follow the manufacturer’s guidelines and use the correct diagnostic tools.
What to know for maintenance or troubleshooting
Understanding the ECU’s location helps with routine checks, diagnostics, and replacement. If you’re diagnosing engine performance issues, the ECU is a central component that coordinates fuel delivery, ignition timing, and various sensors. Accessing it for inspection or replacement typically requires only basic hand tools and some patience to remove protective covers.
Summary
In most Acura TSX models, the ECU is located in the engine bay on the passenger side near the firewall, protected by a plastic cover and mounted to a bracket or inner fender. Access involves removing the protective shield to reveal the multi-pin connectors. Always disconnect the battery before work, consult your year-specific manual for any variations, and seek professional help if you suspect an ECU fault.
