how to fix P0700 transmission code on BMW 3 Series F30/F31 (2012-2019)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the vehicle battery to ensure safety while working on electrical components.

2. Inspect and Replace Transmission Fluid

• Tools Required: Socket set, funnel, drain pan.
• Remove the transmission fluid pan using a socket set.
• Allow the old fluid to drain completely into the drain pan.
• Inspect the fluid for metal shavings or burnt smell, which indicates internal damage.
• Replace with manufacturer-recommended transmission fluid, using a funnel to refill.
• Reinstall the fluid pan with a new gasket, tightening bolts to the manufacturer's specified torque.

3. Check and Repair Wiring

• Tools Required: Multimeter, wire strippers, electrical tape.
• Inspect the wiring harness for any frays or damage.
• Use a multimeter to check for continuity in the wires leading to the TCM.
• Repair any damaged wires using wire strippers and electrical tape, ensuring a good connection.

4. Test and Replace Transmission Control Module (if needed)

• Tools Required: OBD-II scanner.
• Reconnect the battery and clear the P0700 fault code using the OBD-II scanner.
• If the code reappears after a short drive, proceed to remove the TCM.
• Disconnect the TCM connector and remove the module using a socket set.
• Install a new TCM, ensuring all connections are secure and properly seated.

5. Final Steps

• Reconnect the battery and perform a final check of the transmission fluid level.
• Ensure all tools are removed from the engine bay before closing the hood.