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

Solution

1. Preparation

• Gather tools and parts needed.
• Ensure the vehicle is parked on a level surface and secure.
• Disconnect the battery to prevent electrical shorts.

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Multimeter
• Transmission fluid pump
• Fluid catch basin

2. Check and Replace Transmission Fluid

• Check Fluid Level:

  • Remove the transmission dipstick and wipe it clean.
  • Reinsert and remove the dipstick again to check the fluid level.
  • If low, add the appropriate transmission fluid (refer to the owner's manual for specifications).

• Replace Fluid if Contaminated:

  • If the fluid is burnt or contaminated, drain the transmission fluid using a transmission fluid pump into a catch basin.
  • Replace the transmission filter if accessible; remove the pan if necessary (follow the steps in the next section).
  • Refill the transmission with new fluid, ensuring to use the proper type as specified by BMW (usually ATF with specific ratings).

3. Inspect and Repair Wiring/Connections

• Visually inspect the wiring harness connected to the transmission control module.
• Use a multimeter to check for continuity and proper voltage at the TCM connection.
• Repair or replace any damaged wiring or connectors found during inspection.

4. TCM Replacement (if necessary)

• If the TCM is determined to be faulty:
  • Remove the TCM from its mounting location (usually requires removing a few screws).
  • Disconnect the electrical connectors from the TCM.
  • Install the new TCM by reversing the removal process.
  • Ensure all connections are secure and that the unit is properly mounted.

5. Reconnect Battery and Clear Codes

• Reconnect the battery and use the OBD-II scanner to clear the P0700 code and any other related codes stored in the system.
• Perform a test drive to ensure the issue is resolved.