how to diagnose P0700 transmission code on my Volkswagen Golf Seventh Generation (2013-2020)

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, transmission fluid.
• Ensure the vehicle is on a level surface and the engine is off before starting.

2. Fluid Inspection

• Sub-steps:
  1. Locate the transmission dipstick (if applicable) or access the transmission fill plug.
  2. Remove the dipstick or fill plug and check the fluid level; add fluid if low.
  3. Inspect the fluid’s color and smell—if burnt or excessively dark, a fluid change is necessary.
• Safety Warnings: Allow the engine to cool before checking fluid levels.

3. Wiring and Connector Check

• Sub-steps:
  1. Visually inspect the wiring harness connected to the TCM for any signs of wear or damage.
  2. Disconnect the electrical connector and check for corrosion or bent pins.
  3. Use a multimeter to check for continuity in the wiring.
• Safety Warnings: Disconnect the battery before working on electrical systems.

4. TCM Testing

• Sub-steps:
  1. Reconnect the battery and use the multimeter to test voltage at the TCM connector.
  2. Compare voltage readings to the specifications in the service manual.
  3. If readings are out of range, consider replacing the TCM.

5. Fluid Change (if necessary)

• Sub-steps:
  1. Raise the vehicle securely on jack stands.
  2. Drain the old transmission fluid through the drain plug and replace with new fluid as specified in the owner's manual.
  3. Replace the transmission filter (if applicable) and reassemble everything, ensuring all bolts are torqued to specification.
• Parts Required: Transmission fluid, transmission filter.