Metra WM-GM29-SWC GM LAN Data Interface with SWC Installation Instructions

About the Interface

This interface is designed for GM LAN vehicles from 2006 and newer. It is suitable for non-amplified models or models with an analog-activated amplifier.

Interface Features

• Provides accessory power (12-volt 10-amp).
• Retains R.A.P. (retained accessory power).
• Provides wires for multimedia radios (parking brake, reverse, speed sense).
• Retains chimes.
• Retains audio controls on the steering wheel.
• Retains balance and fade.
• Micro-B USB updatable.

Connections

From the WM-GM29-SWC harness to the aftermarket radio, connect the wires as follows:

• Black wire: to the ground wire.
• Yellow wire: to the battery wire.
• Red wire: to the accessory wire.
• Blue wire: to the power antenna wire (LD-GM29A only).
• Blue/White wire: to the amp turn-on wire.
• Orange wire: to the illumination wire (if applicable). (Note: LD-GM29B harness has 3 Orange wires)
• Gray wire: to the front right positive speaker output.
• Gray/Black wire: to the front right negative speaker output.
• White wire: to the front left positive speaker output.
• White/Black wire: to the front left negative speaker output.
• Purple wire: to the rear right positive speaker output.
• Purple/Black wire: to the rear right negative speaker output.
• Green wire: to the rear left positive speaker output.
• Green/Black wire: to the rear left negative speaker output.
• Blue/Pink wire: to the VSS/speed sense wire.
• Green/Purple wire: to the reverse wire.
• Light Green wire: to the parking brake wire.

For Radios with SWC Wires (3.5mm Jack)

• Connect the 3.5mm adapter to the interface's 3.5mm jack.
• Brown wire: connect to the radio wire labeled Key-A, SWC-1, or SWCIR.
• Brown/White wire: connect to the radio wire labeled Key-B or SWC-2 (if applicable).
• Note: After programming, assign SWC buttons in radio settings. XITE radios require SWC-2 to Brown.

For Other Radios

• Connect the 3.5mm jack to the steering wheel control input.

For Vehicles Without Steering Wheel Controls

• Tie the wires from the 3.5mm adapter together.
• Cut pin 5 from the 12-pin harness going into the interface. (Refer to Figure A for pin identification).

Programming

Follow these steps to program the interface:

1. Open the driver's door and keep it open throughout the programming process. Turn the ignition ON.
2. Connect the WM-GM29-SWC harness to the WM-GM29-SWC interface, and then to the vehicle's wiring harness.
3. For models with steering wheel controls:
   • For vehicles requiring a 'hold' action: Press and hold the Volume Up button on the steering wheel until the LED stops flashing.
   • For vehicles requiring a 'tap' action: Tap the Volume Up button on the steering wheel until the LED stops flashing.
4. The LED will flash Green & Red while the interface learns the radio. Once learned, the LED will turn off, flash briefly, and then turn solid Green.
5. The LED will turn off again, then quickly flash Green & Red while the interface learns the vehicle. Once learned, the LED will turn off and then solid Green. Turn the ignition OFF/ON, then test all functions for proper operation.
6. If the interface does not function, press and release the reset button, then repeat the programming process from step 3.

Applications

The following vehicles are compatible with the WM-GM29-SWC interface:

Support

If you encounter difficulties, Metra's technical support is available:

• Phone: 386-257-1187
• Email: techsupport@metra-autosound.com
• Hours (Eastern Standard Time):
  • Monday - Friday: 9:00 AM – 7:00 PM
  • Saturday: 10:00 AM – 7:00 PM
  • Sunday: 10:00 AM – 4:00 PM