how to fix P0700 code on my Toyota Highlander Third Generation (2014-2019)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the vehicle battery to prevent electrical shorts.
• Ensure the vehicle is on a level surface and secure it with wheel chocks.

2. Inspect and Change Transmission Fluid

• Tools Required: Socket set, fluid pump, transmission fluid.
• Sub-steps:
  1. Remove the transmission fluid dipstick and check the fluid level.
  2. If low, add the manufacturer-recommended transmission fluid through the dipstick tube.
  3. If fluid is dirty, drain the transmission fluid using the drain plug.
  4. Replace with fresh transmission fluid, ensuring the correct type and quantity according to the manufacturer's specifications.

3. Repair or Replace TCM

• Tools Required: Torque wrench, socket set, multimeter.
• Sub-steps:
  1. Locate the transmission control module, typically found near the transmission.
  2. Disconnect the electrical connector from the TCM.
  3. Use a multimeter to test for power and ground at the connector.
  4. If the TCM is faulty, remove it by unscrewing the mounting bolts and carefully disconnecting it.
  5. Install the new TCM by reversing the removal process and securing it with bolts.

4. Check and Replace Sensors if Necessary

• Tools Required: Socket set, multimeter.
• Sub-steps:
  1. Inspect the vehicle speed sensor and associated wiring for damage.
  2. Test the sensor with a multimeter to ensure it is within manufacturer specifications.
  3. If defective, remove the sensor, and install a new one by reversing the removal process.

5. Reconnect Battery and Clear Codes

• Reconnect the battery terminals ensuring a tight fit.
• Use an OBD-II scanner to clear the P0700 code and any other related codes.
• Start the vehicle and allow it to idle to ensure the transmission functions properly.