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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a level surface and the engine is off before beginning.
• Disconnect the vehicle's battery to prevent electrical shorts.

2. Inspect and Replace Transmission Fluid

• Tools Required: Transmission fluid pump, drain pan, funnel, socket set
• Steps:
  1. Remove the transmission fluid drain plug and allow fluid to completely drain into the pan.
  2. Inspect the fluid; if it's contaminated or burnt, proceed with a fluid change.
  3. Install the drain plug with the correct torque specification (consult repair manual for torque value).
  4. Refill the transmission with the appropriate type and amount of fluid as per manufacturer's specifications using a funnel.

3. Check and Repair Wiring and Connectors

• Tools Required: Multimeter, wire stripper/crimper, electrical tape
• Steps:
  1. Visually inspect the wiring harness and connectors for any signs of damage or corrosion.
  2. Use a multimeter to test for continuity and proper voltage at the TCM connector.
  3. Repair any damaged wires using a wire stripper and crimper; ensure proper insulation with electrical tape.
  4. Reconnect the harness securely.

4. Replace Transmission Control Module (if necessary)

• Tools Required: Socket set, OBD-II scanner
• Steps:
  1. Remove any covers obstructing access to the transmission control module.
  2. Disconnect the electrical connectors from the TCM.
  3. Unbolt and remove the old module.
  4. Install the new TCM, ensuring it is secured with the correct torque specification.
  5. Reconnect electrical connectors, making sure they are seated properly.

5. Reset the Engine Control Module (ECM)

• Tools Required: OBD-II scanner
• Steps:
  1. Reconnect the vehicle's battery.
  2. Use the OBD-II scanner to clear any stored error codes from the ECM.
  3. Perform a test drive to check for reoccurrence of the P0700 code.