how to troubleshoot P0700 transmission trouble code in my Toyota Tacoma N300 (2016-Present)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and securely supported with jack stands.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Check Transmission Fluid

• Sub-steps:
  • Remove the transmission dipstick.
  • Check the fluid level; add fluid if low, ensuring the correct type (Toyota ATF WS).
  • Inspect fluid condition; if dark or burnt, a fluid change is needed.

3. Inspect Wiring and Connectors

• Sub-steps:
  • Visually inspect the wiring harness leading to the TCM for any frays or breaks.
  • Disconnect the connectors and clean them with electrical contact cleaner.
  • Reconnect ensuring a secure fit.

4. Test the TCM

• Sub-steps:
  • Reconnect the negative battery terminal.
  • Use a specialized diagnostic scanner to check for TCM functionality.
  • If faulty, replace the TCM with an OEM part.

5. Replace Transmission Fluid (if required)

• Sub-steps:
  • Drain the old transmission fluid using a drain pan.
  • Remove the transmission pan (if necessary) and replace the transmission filter.
  • Reinstall the pan with a new gasket and torque to specifications (typically 10-12 ft-lbs).
  • Refill with the correct type and amount of transmission fluid.

Tools Required:

• OBD-II scanner
• Multimeter
• Socket set
• Torque wrench
• Transmission fluid pump
• Drain pan

Parts Required:

• Transmission fluid (Toyota ATF WS)
• Transmission filter (if replaced)
• TCM (if faulty)

Estimated Repair Time: 2-4 hours

Safety Warnings:

• Disconnect battery before working on electrical systems.
• Allow the engine to cool before working on the transmission.