how to deal with Toyota Highlander Fourth Generation (2020-present) P0700 transmission trouble code

Solution

1. Preparation

• Gather tools and parts needed.
• Disconnect the battery to ensure safety.
• Raise the vehicle using a jack and secure it with jack stands.

2. Transmission Fluid Inspection and Change

• Remove the transmission dipstick and check fluid level.
• If fluid is low or burnt, drain the old transmission fluid using a drain pan.
• Replace with new fluid recommended for the Highlander (check owner's manual for specifications).
• Recheck fluid level after replacing.

3. Wiring and Connector Repair

• Inspect the wiring harness for the TCM and transmission for any frays or breaks.
• Clean any corroded connectors and repair wiring as necessary using heat-shrink tubing or soldering.
• Ensure all connections are secure and free from moisture.

4. TCM Testing and Replacement

• If wiring is intact, test the TCM using a multimeter to check for proper voltage and ground.
• If the TCM is faulty, remove it by unbolting the mounting screws and disconnecting the wiring harness.
• Install the new or refurbished TCM, ensuring it is properly seated and secured.

5. Reassemble and Reset Codes

• Reconnect the battery.
• Use the OBD-II scanner to clear any stored trouble codes.
• Perform a thorough test drive to ensure proper shifting and operation.