Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2012 BMW 335xi Standard TransFACTORY OEM SERVICE PROCEDURE
System overview
The following graphic shows a system overview of the ignition in engine N55:
| Index | Explanation |
|---|---|
| 1 | Power distribution box, engine compartment |
| 2 | Ignition and injection relay |
| 3 | Digital engine electronics (DME) |
| 4 | Spark plug, cylinder 1 |
| 5 | Ignition coil, cylinder 1 |
| 6 | Spark plug, cylinder 2 |
| 7 | Ignition coil, cylinder 2 |
| 8 | Spark plug, cylinder 3 |
| 9 | Ignition coil, cylinder 3 |
| 10 | Spark plug, cylinder 4 |
| 11 | Ignition coil, cylinder 4 |
| 12 | Spark plug, cylinder 5 |
| 13 | Ignition coil, cylinder 5 |
| 14 | Spark plug, cylinder 6 |
| 15 | Ignition coil, cylinder 6 |
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.