how to fix my BMW 3 Series F30/F31 (2012-2019) rear lights not working

BMW 3 Series F30/F31 (2012-2019)

Error Codes

1-2 hours

Time

medium

Difficulty

medium

Severity

3 min read

546 words

Problem Statement

The rear lights on a BMW 3 Series F30/F31 (2012-2019) are not functioning, potentially affecting visibility and safety.

Estimated Time

1-2 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

•Disconnect battery before working on electrical systems.
•Ensure the vehicle is off and cool before starting repairs.

Symptoms

•No illumination of rear brake lights
•No illumination of rear turn signals
•No illumination of rear parking lights
•"Check rear lights" warning message on the dashboard
•Blinking of turn signal indicator at a faster rate (if applicable)

Diagnostic Steps

1
Inspect the rear light bulbs for any signs of burning out or failure.
2
Check the fuse related to the rear lights using the fuse box diagram.
3
Scan the vehicle’s computer using an OBD-II scanner for any error codes related to the lighting system.
4
Inspect the wiring harness and connectors for any signs of damage, corrosion, or loose connections.
5
Test the rear light switch for proper functionality.

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

Verification

After completing the repair, verify that the issue has been resolved:

✓Test the affected component to ensure it functions correctly
✓Check for any error codes or warning lights
✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

•Follow the manufacturer's recommended maintenance schedule
•Address warning signs early before they develop into major issues
•Use quality parts and fluids recommended for your vehicle
•Keep detailed records of all repairs and maintenance

Tools & Equipment Required

•Sub-steps:**
•Locate the fuse box, which can be found in the glove compartment or under the dashboard.
•Use the fuse diagram to identify the fuse for the rear lights.
•Reinstall the fuse and close the fuse box.

Parts Required

•Replacement light bulbs (P21W, PY21W)
•Replacement fuse (if blown)
•Wiring harness (if damaged)

Related Faults

Share this solution

Comments

No comments yet

Be the first to share your thoughts

Back to Generation

Diagnostic Steps

1
Inspect the rear light bulbs for any signs of burning out or failure.
2
Check the fuse related to the rear lights using the fuse box diagram.
3
Scan the vehicle’s computer using an OBD-II scanner for any error codes related to the lighting system.
4
Inspect the wiring harness and connectors for any signs of damage, corrosion, or loose connections.
5
Test the rear light switch for proper functionality.

Solution

1. Preparation

Gather all necessary tools and parts.
Disconnect the negative terminal from the battery to ensure safety while working on electrical components.

2. Inspect and Replace Bulbs

Sub-steps:
1. Remove the rear light assembly by unscrewing the retaining screws.
2. Carefully pull the assembly outwards to access the bulbs.
3. Remove the failed bulbs and replace them with new bulbs of the same type (typically P21W for brake lights, PY21W for turn signals).
4. Reinstall the light assembly and secure it with screws.

3. Check and Replace Fuse

Tools Required: Fuse puller or needle-nose pliers
Sub-steps:
1. Locate the fuse box, which can be found in the glove compartment or under the dashboard.
2. Use the fuse diagram to identify the fuse for the rear lights.
3. Remove the fuse and inspect it for continuity; if it is blown, replace it with a fuse of the same amperage.
4. Reinstall the fuse and close the fuse box.

4. Repair Wiring and Connections

Sub-steps:
1. Inspect the wiring harness leading to the rear lights for any visible damage.
2. If damaged, cut out the damaged section and splice in new wire using solder and heat shrink tubing.
3. Clean any corroded connectors with electrical contact cleaner and ensure all connections are secure.

5. Test Rear Light Switch

Tools Required: Multimeter
Sub-steps:
1. Remove the switch panel from the dashboard.
2. Use a multimeter to test for continuity on the switch terminals while toggling the switch.
3. If the switch is faulty, replace it with a new one.