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

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, fluid catch pan, socket set, torque wrench.
• Ensure the vehicle is parked on a level surface and the engine is off.
• Disconnect the battery to prevent electrical shorts.

2. Check and Replace Transmission Fluid

• Remove the transmission fluid dipstick.
• Check the fluid level; if low, add the manufacturer-recommended transmission fluid.
• If the fluid is dark or burnt, drain the transmission fluid into a catch pan.
• Replace with new fluid as per manufacturer specifications.

3. Inspect and Repair Wiring

• Visually inspect the wiring harness and connectors leading to the TCM.
• Repair any frayed wires or corroded connectors.
• Ensure all connections are tight and clean.

4. Test and Replace Transmission Solenoids

• Disconnect the electrical connectors from the solenoids.
• Use a multimeter to check for continuity and resistance according to specifications.
• If any solenoid is found defective, replace it with a new unit.

5. Reconnect and Clear Codes

• Reconnect the battery and all connectors.
• Use an OBD-II scanner to clear any stored trouble codes.
• Start the engine and allow it to reach normal operating temperature.