how to fix P0700 transmission code on my Toyota Highlander XU70 (2020-Present)?

Solution

1. Preparation

• Gather tools and parts.
• Ensure the vehicle is on a level surface and the parking brake is engaged.
• Disconnect the battery to prevent electrical shorts.

Tools Required:

• OBD-II scanner
• Multimeter
• Socket set
• Torque wrench
• Fluid pump (for refilling transmission fluid)

2. Transmission Fluid Check

• Remove the transmission dipstick or fill plug.
• Check the fluid level; if low, add the correct type of ATF (consult the owner's manual for specifications).
• Inspect the fluid color and smell. If it’s dark or smells burnt, consider a fluid change.

3. Wiring and Connector Inspection

• Visually inspect the wiring harness connected to the TCM and transmission.
• Disconnect and clean the connectors if corrosion is present.
• Repair or replace any damaged wiring as necessary.

4. TCM Testing

• Reconnect the battery and turn the ignition to the ON position without starting the engine.
• Use a multimeter to check the voltage at the TCM connector; ensure it matches specifications.
• If the voltage is incorrect, trace the wiring back to the source.

5. Solenoid Inspection

• If applicable, remove the transmission pan to access the solenoids.
• Remove the solenoids and test their resistance with a multimeter according to manufacturer specifications.
• Replace any solenoids that are outside the specified resistance range.

6. Clear Codes and Test Drive

• Use the OBD-II scanner to clear the P0700 code and any other codes present.
• Take the vehicle for a test drive to monitor the transmission behavior and check for reoccurring codes.