how to fix P0700 code on my Toyota Highlander Fourth Generation (2020-present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts during repairs.

2. Check and Replace Transmission Fluid

• Sub-steps:
  1. Raise the vehicle using a jack and secure it with jack stands.
  2. Locate the transmission dipstick or fill plug.
  3. Remove the dipstick; check the fluid level and condition.
  4. If fluid is low or burnt, drain the transmission fluid using a drain pan.
  5. Replace with new manufacturer-recommended transmission fluid and refill to the proper level.

3. Inspect and Repair Wiring and Connectors

• Sub-steps:
  1. Visually inspect the wiring harness connected to the TCM for any signs of wear or damage.
  2. Disconnect the connectors and clean them with electrical contact cleaner.
  3. Repair or replace any damaged wires or connectors.

4. Test and Replace Transmission Control Module (if necessary)

• Sub-steps:
  1. If the TCM is determined to be faulty, remove it from its mounting location.
  2. Disconnect the electrical connectors carefully.
  3. Install the new TCM by connecting the wiring harness and securing it in place.
  4. Reconnect the battery terminal.

5. Clear Codes and Test Drive

• Sub-steps:
  1. Use the OBD-II scanner to clear the P0700 code from the vehicle's computer.
  2. Start the engine and take the vehicle for a test drive to ensure proper transmission operation.