Poor Fuel Economy
WARNING: This page is about a different car, the 2018 Chevrolet Suburban 3500 HD. However, it is still accessible from the selected car via links, so may be relevant.
- Observe the Throttle Body Idle Airflow Compensation parameter with a scan tool. A value greater than 90% may indicate an excessive accumulation of deposits in the throttle bore. Inspect the throttle body and bore and clean, if necessary. Refer to Throttle Body Cleaning .
- Inspect for heavy loads being carried or towed.
- Inspect for acceleration rate too much or too often.
- Inspect for incorrect operation of the speedometer.
- Inspect the brake system for brake drag.