Where is the speed sensor wire on a 2003 GMC pickup?

The location of the speed sensor wire on a 2003 GMC pickup depends on whether it's a 2WD or 4WD truck, and the specific transmission type (automatic or manual). There isn't one single universally applicable answer.

To find it, you'll need to consult a repair manual specific to your GMC truck's year, make, model, and drivetrain. These manuals provide diagrams showing the sensor's location and wiring harness.

General Possibilities:

* For vehicles with automatic transmissions, the Vehicle Speed Sensor (VSS) is often located on the transmission itself. It could be on the side, top, or rear.

* For vehicles with manual transmissions, the VSS might be located on the transmission, the transfer case (4WD), or even integrated into the speedometer cable.

* 4WD trucks may have additional sensors (like a transfer case speed sensor).

Without the specific details of your truck (engine, transmission, 2WD/4WD), a more precise answer is impossible. Trying to locate it without a manual risks damaging other components. A repair manual is your best and safest resource. You can find these manuals online (often as PDFs) or at auto parts stores.