how to troubleshoot P0700 transmission code in BMW 3 Series E90/E91 (2005-2012)

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative terminal of the battery to prevent electrical shorts.
• Ensure the vehicle is on a level surface and secure it with wheel chocks.

2. Inspect Transmission Fluid

• Remove the transmission fluid dipstick and check fluid level.
• If fluid is low, add the appropriate type of fluid (refer to the owner’s manual for specifications).
• If fluid appears dark or contaminated, a fluid change may be necessary.

3. Check Wiring and Connectors

• Visually inspect the wiring harness leading to the TCM and solenoids for frays or breaks.
• Disconnect the connectors and clean them with electrical contact cleaner.
• Reconnect and secure all connections ensuring they are tight.

4. Test the TCM

• Using a multimeter, check the voltage at the TCM connectors while operating the vehicle.
• Consult the service manual for the specific voltage requirements for your model.
• If readings are outside the normal range, replace the TCM.

5. Inspect and Test Solenoids

• Remove the transmission pan to access the solenoids.
• Inspect each solenoid for signs of wear or damage.
• Measure the resistance across each solenoid terminals; compare with specifications.
• Replace any faulty solenoids.

6. Clear Codes and Test Drive

• Use the OBD-II scanner to clear the P0700 code and any other related codes.
• Reconnect the battery and perform a test drive to monitor transmission performance.