what causes my BMW 3 Series F30/F31 (2012-2019) transmission to slip

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and secure it with wheel chocks.
• Disconnect the battery to ensure safety during the repair.

2. Check and Replace Transmission Fluid

• Tools Required: Transmission fluid pump, funnel, drain pan.
• Remove the transmission drain plug and drain the old fluid into the pan.
• Inspect the fluid for contamination; if it appears burnt, a full fluid change is necessary.
• Replace the drain plug and refill the transmission with the recommended fluid type (usually OEM ATF).
• Use a transmission fluid pump and funnel to fill until the correct level is achieved through the fill port.

3. Replace Transmission Filter

• Tools Required: Socket set, ratchet, wrench set.
• Remove the transmission pan by unscrewing the bolts securing it.
• Clean the pan thoroughly and inspect for metal shavings or debris.
• Remove the old filter and replace it with a new one, ensuring that the gasket is also replaced.
• Reinstall the transmission pan with a torque wrench, tightening to manufacturer specifications.

4. Inspect and Repair Electrical Connections

• Tools Required: Multimeter, wire brush.
• Check electrical connections to the TCM for corrosion or damage.
• Clean any corroded connectors and ensure tight connections.
• If necessary, replace any damaged wiring or connectors.

5. Reconnect Battery and Test Drive

• Reconnect the battery.
• Conduct a test drive to ensure the transmission engages smoothly and does not slip.