what to do if my Volkswagen Golf MK7 (2015-2019) has a check engine light for P0700

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, multimeter, transmission fluid dipstick.
• Safety Warnings: Disconnect the battery before working on electrical systems.

2. Inspect and Replace Transmission Fluid

• Check the fluid level using the dipstick and ensure the fluid is bright red and has no burnt smell.
• If fluid is low or dirty, drain the old fluid and replace it with the manufacturer-recommended transmission fluid.
  • Sub-steps:
  • Raise the vehicle securely on jack stands or ramps.
  • Place a drain pan beneath the transmission pan.
  • Remove the transmission fluid pan bolts and carefully lower the pan.
  • Allow old fluid to drain completely.
  • Replace the filter if necessary, according to manufacturer specifications.
  • Reinstall the pan with new gasket material, tightening bolts to the specified torque.
  • Refill the transmission with new fluid through the dipstick tube.

3. Inspect and Repair Wiring and Connectors

• Examine the wiring harness connected to the TCM for any fraying, corrosion, or loose connections.
  • Sub-steps:
  • Disconnect the TCM connector and inspect for any signs of damage.
  • Use a multimeter to check continuity on the wiring to ensure there are no breaks.
  • Repair or replace any damaged wiring or connectors as necessary.

4. Replace the Transmission Control Module (if necessary)

• If the TCM is confirmed to be faulty, proceed with replacement.
  • Sub-steps:
  • Disconnect the battery.
  • Remove the faulty TCM from its mounting location.
  • Install the new TCM, taking care to connect all wiring correctly.
  • Reconnect the battery and ensure all connections are secure.