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

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is turned off.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Check and Replace Transmission Fluid

• Tools Required: Transmission fluid pump, funnel.
• Sub-steps:
  1. Locate the transmission dipstick or fill plug.
  2. Remove the dipstick or fill plug and check fluid level; add fluid if low.
  3. If fluid is dark or has a burnt smell, replace it.
  4. Drain the old fluid using a fluid pump or by removing the drain plug.
  5. Replace the transmission filter if applicable (consult service manual).
  6. Refill with the correct type of transmission fluid (typically Toyota ATF WS).

3. Inspect and Repair Electrical Connections

• Tools Required: Multimeter, socket set.
• Sub-steps:
  1. Visually inspect the wiring harness and connectors for any signs of wear or damage.
  2. Use a multimeter to check for continuity in the wiring.
  3. Repair or replace any damaged wires or connectors as necessary.

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

• Tools Required: OBD-II scanner, socket set.
• Sub-steps:
  1. Clear the P0700 code using the OBD-II scanner and take the vehicle for a test drive.
  2. If the code returns, consider replacing the TCM.
  3. Remove the old TCM by unscrewing the mounting bolts and disconnecting the electrical connectors.
  4. Install the new TCM and ensure all connections are secure.
  5. Reconnect the negative battery terminal.