how to fix P0700 transmission trouble code in Toyota Highlander Fourth Generation (2020-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Inspect and Replace Transmission Fluid

• Sub-steps:

  1. Raise the vehicle securely on jack stands.
  2. Locate the transmission fluid pan and remove the drain plug (if equipped).
  3. Allow the fluid to drain completely into a suitable container.
  4. Inspect the fluid for contaminants; replace it if it appears burnt or dirty.
  5. Reinstall the drain plug and refill the transmission with the manufacturer-recommended fluid using a funnel.

• Tools Required:

  • Socket set
  • Fluid pump (for refilling)

3. Address Transmission Control Module (TCM) Issues

• Sub-steps:

  1. Remove the TCM from its mounting location.
  2. Inspect the connectors for corrosion or damage; clean or repair as necessary.
  3. Reinstall the TCM and ensure that it is securely fastened.
  4. If needed, replace the TCM with a new one by disconnecting the old unit and connecting the new unit using the same connectors.

• Tools Required:

  • Screwdrivers
  • Torque wrench (optional for reinstallation)

4. Clear Codes and Test Drive

• Sub-steps:
  1. Reconnect the negative battery terminal.
  2. Use the OBD-II scanner to clear the P0700 trouble code.
  3. Take the vehicle for a test drive to ensure that the transmission operates correctly and the check engine light does not reappear.