Where is the ecu on a 1990 Chevy silverado?

The ECU (Engine Control Unit) on a 1990 Chevy Silverado is typically located under the dashboard on the driver's side, near the steering column. It is often mounted on or near the firewall. In some configurations, it may also be found in the engine compartment, depending on the specific model and options. Always consult the vehicle's service manual for exact locations and details.