How to make your ZCP/CSL M-Track Mode button illuminated.
It is necessary to remove your headlight switch, upper and lower steering column trim and the lower dash panel to complete this procedure. This guide does not include the process to accomplish the removal of those items and only focuses on the actual work needed to illuminate the M-Track button.
For those of you who own a Competition Package E46 M3 in the United States or a CS or CSL in Europe, you may have noticed that the M-Track button on your steering wheel is not illuminated.
When I bought my ZCP E46 M3, one of the first things that I noticed was that the M-Track button was not illuminated along with the other interior buttons. After looking closely at the button I could see that the “I/O” was not silk screened on, but that it was a separate transparent piece of plastic similar to the other buttons within the interior.
After removing the steering wheel trim I removed the switch by unscrewing the four small silver screws on the back that holds the button to the trim. I then put a small light behind the button to see if it was, in fact, transparent.
This picture clearly shows that the button can be illuminated.
After removing the switch circuit board from the trim I plugged the electrical connector in the steering wheel back into the switch circuit board and placed it into position.
I then removed the rubber cover from the switch circuit board.
Here you can see the small surface mount LED at location “D4” on the circuit board right where the M-Track button sits. This clearly shows that BMW possibly had an intention to illuminate the M-Track button, but never went through with it. After looking at wiring diagrams related to the multifunction buttons in other E46 3 series, I determined what needed to be wired up.
After removing the lower steering column trim you can see a small 10-pin green connector near the 6 o’clock position of the steering wheel. This is connector X10170. If you have an SMG II transmission, you will see a smaller 2-pin bordeaux connector (X10171) next to the X10170 connector. Unplug these connectors.
On ZCP and CSL E46 M3s, wires 7 through 10 go directly to the M-Track button, but wires 9 and 10 are not used on the 10-pin X10170 connector as seen in the picture below. Wire 7 is ground for the button and wire 8 controls M-Track mode. Wires 9 and 10 are going to be added to the connector. Wire 9 is for I-BUS which controls the dimming and wire 10 is for power.
You will need two wires with pin contacts to add to the X10170 connector. The BMW part number is 61130005197. I used two spare wires from an E46 cluster harness. If you reuse wires from another harness, clean the wire with acetone and a cloth to remove any residue left behind by electrical tape.
Before you press the wires in, you will need to lift the locking plate on the X10170 connector to allow the wires to click all of the way in.
Wires 9 and 10 will be tapped in to two wires in the X12 connector for the headlight switch.
Since my spare wires were too short, I added a length of wire by twisting the ends together, folding them over and heat shrinking them.
It is up to you to decide how you want to run your wires. I ran the two wires along the bundle of wires in the plastic holder attached to the steering column all the way to the headlight switch harness. This can be seen in the pictures below.
The wire from pin 9 in the X10170 connector will be tapped to the white/red/yellow wire located at pin 21 of the X12 connector and the wire from pin 10 in the X10170 connector will be tapped to the violet/yellow wire located at pin 27 of the X12 connector. To access those wires, the black cover needs to be removed from the plug. This can be achieved by prying up on both bottom edges and sliding off. This will reveal smaller blue and brown connectors. Pin 21 and pin 27 are located on the blue connector.
It is up to you to decide how you want to tap into these wires. I located both wires and shaved a small amount of insulation about three inches away from the connector on both sides of the wire. I then carefully pushed a straight pick through to create a small hole.
Then I slid the wire through the exposed hole and wrapped it around. I removed wires 21 and 27 from the blue connector so I could heat shrink them.
Push the wires back into their respective places in the blue connector and slide the black cover back over the blue and brown connectors. It is easiest if you slide it over both the blue and brown connectors at the same time. Reconnect the headlight switch.
To test if the light works, turn your key to position 1 and turn your parking lights on. The M-Track button should illuminate. Move the dimmer switch to make sure that the button dims as well.
Below is the light on the brightest setting.
Below is the light on the dimmest setting.
Originally, I just ran the wire for power from pin 10 on the X10170 connector to pin 27 on the X12 connector. This caused the M-Track button to illuminate whenever the key was in position 1 or 2 and it did not respond to the dimmer switch. This is why pin 9 of the X10170 connector needs to be tapped into pin 21 of the X12 connector. The dimming signal is sent over I-BUS which makes pin 9 necessary. With pin 9 tapped, this causes the M-Track button to only illuminate when the parking lights or headlights are on and for the button to dim along with the other interior buttons. If you just want your button to be illuminated all of the time and do not care if it dims or not, then you can get by with just tapping power from pin 10 of the X10170 connector to pin 27 of the X12 connector.
I hope you enjoyed this guide for the first documented process of illuminating the M-Track button for ZCP, CS and CSL E46 M3 models.