BMW E46 Reverse Light Switch Wire Harness

Doing an automatic to manual conversion on a BMW E46 is quite easy when you have all of the correct parts, such as a Manual Transmission Wire Harness. However, there are multiple versions of the E46 manual transmission wire harness; MS42, MS43 with bolt-in coils, MS43 with pencil coils, and MS45. Sometimes finding the correct manual transmission wire harness can be challenging and/or expensive.

Technically the E46 will work with the original automatic transmission wire harness in place after doing a manual conversion, except for the Reverse Lights. The automatic transmission wire harness has a Reverse Light Relay which is triggered by the transmission control unit. While the manual transmission wire harness has the power for the reverse lights going straight to and from the reverse light switch in the transmission, rather than to and from the automatic reverse light relay contacts.

This wire harness can be used to add the wiring and connector for the manual reverse light switch connector to an automatic transmission wire harness, which at the same time you can remove all of the extra automatic wiring from the transmission wire harness and therefore convert the automatic transmission wire harness to a manual transmission wire harness.

Connector Pinout:

1. – 1.00 mm² Blue – to X6021-3 (pre-crimped pin*)
2. – 1.00 mm² Green – to X6021-4 (pre-crimped pin*)

Notes:

 – X6021 is the 4-pin Black connector that goes between the transmission wire harness and chassis wire harness inside of the E-box.

* The X6021 connector is different on MS42 than the MS43, MS45, or MSS54 (M3). The MS42 connector uses round pins rather than these flat pre-crimped pins. To use this harness on a MS42 E46 you will need to cut these pins off and splice the wires as mentioned below. If there was enough demand for a MS42 specific version of this harness with the correct round pins to properly re-pin X6021 we can make it.

 – Installing this harness can either be done by depinning your original Blue/Yellow and Green/White wires from the X6021 connector on the transmission wire harness and inserting these new pins in their place (preferred method, although slightly tricky to depin with a dual prong tool and also lifting the secondary lock of the connector at the same time) or by more easily cutting these pre-crimped pins off and splicing these wires into your original wires between the X6021 connector and automatic reverse light relay.