how to fix P0700 error code in my Toyota Highlander XU70 (2020-Present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is on a level surface and the engine is off.
• Disconnect the battery to avoid electrical shorts.

2. Inspect and Replace Transmission Fluid

• Tools Required: Socket set, transmission fluid pump, funnel
• Sub-steps:
  1. Remove the transmission fluid dipstick and check fluid level and color.
  2. If necessary, drain the old transmission fluid using a fluid pump.
  3. Replace the fluid with the manufacturer-recommended transmission fluid type (typically Toyota ATF WS).
  4. Reinsert the dipstick and check the level again.

3. Inspect and Repair Wiring/Connectors

• Tools Required: Wire stripper/crimper, multimeter
• Sub-steps:
  1. Remove the protective cover to access the wiring harness connected to the transmission control module.
  2. Inspect each wire for frays, corrosion, or breaks; repair or replace any damaged sections.
  3. Ensure all connectors are securely attached and free from dirt or moisture.

4. Replace Transmission Control Module (if necessary)

• Tools Required: Socket set, torque wrench
• Sub-steps:
  1. Locate the transmission control module, typically mounted on or near the transmission.
  2. Disconnect the electrical connectors and remove the mounting bolts.
  3. Install the new transmission control module by reversing the removal steps, ensuring a secure fit.
  4. Torque the mounting bolts to the manufacturer’s specifications.

5. Reconnect Battery and Clear Codes

• Reconnect the vehicle's battery terminals.
• Use an OBD-II scanner to clear any fault codes from the system.