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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent any electrical shorts.
• Ensure the vehicle is on a level surface and secure with jack stands if needed.

2. Transmission Fluid Change

• Sub-steps:
  1. Drain the old transmission fluid using a drain pan.
  2. Replace the transmission fluid filter if applicable.
  3. Refill the transmission with the correct type and amount of fluid (Toyota ATF WS).
• Tools Required: Socket set, fluid pump, drain pan.

3. Inspect and Repair Wiring

• Sub-steps:
  1. Visually inspect the wiring harness connected to the TCM for any signs of wear or damage.
  2. Repair or replace any damaged wiring or connectors.
  3. Clear any stored codes using the OBD-II scanner.
• Tools Required: Multimeter, wire strippers/crimpers, electrical tape.

4. TCM Replacement (if necessary)

• Sub-steps:
  1. Remove the TCM by unscrewing it from its mounting location.
  2. Disconnect the electrical connectors carefully.
  3. Install the new TCM by connecting the electrical connectors and securing it in place.
• Tools Required: Socket set, screwdriver set.

5. Final Checks

• Reconnect the negative battery terminal.
• Start the vehicle and let it idle to check for any warning lights.
• Test drive the vehicle to confirm that the transmission is functioning correctly.