2012 BMW 335xi Automatic TransFACTORY OEM SERVICE PROCEDURE

System overview

The following graphic shows a system overview of the ignition in engine N55:

Fig 1: Spark Plug - Circuit Diagram
G09871881Courtesy of BMW OF NORTH AMERICA, INC.
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.

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

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