Drive By Wire (DBW)

Drive‑By‑Wire (DBW): an electric motor controls the throttle blades. The gas pedal is a sensor that sends input to the TAC (Throttle Actuator Control) module. The TAC reads the pedal, tells the throttle motor how far to open, and communicates with the PCM. If TAC and PCM don’t communicate, the throttle won’t operate and PCM fault codes will set.

DBW timeline:

  • 1997: Corvette

  • ~2001: some higher‑end SUVs

  • 2003: all pickup trucks

  • 2004: some Express vans (usually AWD with traction control)

  • 2007: all vans DBW (most vans used mechanical throttle through 2006)

When buying a motor from a salvage yard, also get the gas pedal assembly, TAC module, and the short pedal‑to‑TAC harness (it passes through the firewall with a rubber grommet). The rest of the wiring is in the engine harness.

Typical wiring (2004 C/K 4.8/5.3/6.0) and DBW differences:

  • DBW introduced to trucks around 2000 (Corvette in 1997)

  • 2000–2002 throttle body: two connectors — 2‑pin passenger, 6‑pin driver

  • 2003+ throttle body: single 8‑pin connector on passenger side

  • TAC modules:

    • 1999–2002: all‑plastic (interchangeable)

    • 2003–2006 (and 2007 Classic): plastic with metal mounting bracket (interchangeable)

Automotive electronic control module with connectors

TAC MODULE 99-02

Car engine control unit with connectors in a white background.

TAC MODULE 2003-2007

Car accelerator pedal assembly on a white background.

2003-05 Pedal

Black electronic control module with connectors
Black electronic control module with metal mounting brackets on white background.

Pedal Harness

Car accelerator pedal with electronic sensor

2006-07 Pedal (Classic Body Style Trucks)