How to Replace a Toyota Avalon ECU

Replace a Toyota Avalon ECU

The ECU, or engine control unit (also known as the engine control module), is a small computer that controls the major functions in your vehicle. The Toyota Avalon has many functions controlled by the ECU; a faulty ECU can make your vehicle inoperable. Replacing the Avalon's ECU may vary slightly from year to year, but the basics will be the same no matter what year-model it is.

Difficulty:

Moderately Easy

Instructions

things you'll need:

• Pliers
• Phillips-head screwdriver
• Socket wrench set
• Replacement ECU

1. • 1

     Remove the battery cover to access the battery terminals. Disconnect the negative (-) battery cable with the pliers.

   • 2

     Open the glove box door and squeeze the outer part to remove the door. Locate the two screws behind the door to remove the glove box.

   • 3

     Access the ECU behind the glove box. Remove the electrical connectors by hand; remove the bolts mounting the ECU to the inner dash.

   • 4

     Install the new ECU in the same position. Replace the bolts and reconnect the electrical connectors.

   • 5

     Replace the glove box and the glove box door. Reconnect your battery.

Tips & Warnings

• Make sure your replacement ECU is compatible with your vehicle. Different Avalon models may have different ECUs. Provide your VIN to the place you purchase the ECU from to ensure compatibility.

• Do not perform this without disconnecting the negative (-) battery cable. This prevents possible electrical shock.