how to fix P0700 code on Volkswagen Passat B8 (2015-2022)

Learn how to diagnose and fix P0700 transmission fault in Volkswagen Passat B8 (2015-2022). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Ensure the vehicle is on a level surface and secure it with jack stands if needed.

2. Fluid Change

• Sub-steps:
  1. Remove the transmission fluid pan by loosening the bolts using a socket set.
  2. Drain the old transmission fluid into a suitable container.
  3. Replace the transmission filter according to manufacturer specifications.
  4. Clean the pan and magnet, removing any debris.
  5. Reinstall the pan with a new gasket, tightening bolts to the recommended torque specification (typically 8-10 Nm).

3. TCM Inspection

• Sub-steps:
  1. Locate the transmission control module (usually found near the transmission).
  2. Disconnect the wiring harness carefully.
  3. Inspect the connectors for corrosion or damage; clean or replace as necessary.
  4. If necessary, replace the TCM with a new unit, ensuring proper alignment and connection.

4. Solenoid Check

• Sub-steps:
  1. Remove the access panel to reach the transmission solenoids.
  2. Using a multimeter, check the resistance of each solenoid according to the specifications in the service manual.
  3. Replace any faulty solenoids with new ones, ensuring proper orientation and connection.

5. Final Checks

• Sub-steps:
  1. Refill the transmission with new fluid, using the manufacturer-recommended type (usually VW G052162 A2 or equivalent).
  2. Reconnect the negative battery terminal.
  3. Start the engine and let it idle for a few minutes, checking for leaks from the transmission pan.
  4. Test drive the vehicle to ensure smooth shifting and verify that the check engine light is no longer illuminated.