E46 MS43 Bolt-in to Pencil Coil Wire Harness Plug and Play Adapter

The M54 engine came equipped with two different style coils, Bolt-In or Pencil style, depending on the build date. Due to the difference of the coils the valve cover also differs for Bolt-In or Pencil style coils. Additionally the different coils use different style electrical connectors and therefore different ignition coil wire harnesses. Besides the different style coil connector, the 2-pin power and ground connector of the ignition coil wire harness varies depending on which version of the ignition coil wire harness it is.

Variations: Build Date Range – Ignition Coil Type – Wire Harness Identifier

• E46 Rear Wheel Drive 325 or 330:
  • Up To 09/2002 – MS43 – Bolt-In Coils – White 2-pin Connector with Round Pins
  • From 09/2002, Up To 03/2003 – MS43 – Pencil Coils – White 2-pin Connector with Flat Pins (this item)
  • From 03/2003 – MS45 – Pencil Coils – Black 2-pin Connector with Flat Pins

This 2-pin Connector on the Ignition Coil Wire Harness plugs into the Transmission Wire Harness inside of the E-Box. When you have the correct version of these different harnesses everything will plug in correctly and work, however a common scenario is a SE46 that originally had Bolt-In Coils which is installing a newer replacement engine that has Pencil Coils. At this point you can either replace the valve cover to use the bolt-in coils, or you can keep the pencil coils.

In this scenario the correct ignition coil wire harness does exist for MS43 DME with Pencil Coils, which is easy to replace and match the pencil coils on the replacement engine, except that this 2-pin connector will not mate with your connector on your original transmission wire harness. The correct transmission wire harness does also exist as well, but it is not as readily available and is slightly more involved to replace.

This plug and play adapter will allow the MS43 Pencil Coil Wire Harness to directly plug into your MS43 Bolt-In Coil Transmission Wire Harness without any cutting or permanent modifications. However, you will need a MS43 DME of Index 04 or above (printed on the label on the DME).

How To Install (Refer to the additional photos above, labeled Step 1 and Step 2):

1. Unclip your original white 2-pin connector from the white 8-pin connector on your transmission harness. Plug in the adapter to your original white 2-pin connector and push the wiring downwards to allow the new white 2-pin connector to clip onto the white 8-pin connector. Note: The beige piece that the white 8-pin connector is clipped onto can be lifted upwards out of the e-box to allow more room.
2. The loose red wire from the plug and play adapter is long enough to neatly route it with the original wiring and has to be added to the DME X60002 connector, at Pin 12. X60002 is also part of the transmission wire harness and is the black 24-pin with the O2 wiring, which is the smallest of the three connectors at the DME with the lever lock. You will need to disconnect the other DME connectors from the opposite side to allow the lever locks to fully pivot and release the connectors. Once X60002 is unplugged from the DME, you will need to slide out the inner gray piece of the connector which is held in by a small clip on the side of the connector. A small flat head screwdriver or pick will easily pry this clip outwards as you slide the inner gray piece out. Notice that this inner gray piece is numbered 1-6 and 7-12. Simply push this loose pre-crimped pin into the location numbered 12 until it is fully inserted and clips into place. Reinsert the gray inner piece and reconnect all of the connectors at the DME in the reverse order than they were disconnected.

Notes:

 – The extra loose wire to X60002-12 is present on the correct MS43 Pencil Coil Transmission Harness and acts as a switch within the DME. When the DME sees this +12V at this pin it causes the DME to use a different set of values for the pencil coils than the bolt-in coils.

 – This adapter can be fully removed but the pin at X60002-12 would need to be depinned. However, you can leave this pin in place while securing the adapter out of the way if you later swap back to bolt-in coils again, as without the adapter plugged in there would be no +12v provided to the pin at X60002-12.