Poor Fuel Economy
WARNING: This page is about a different variant/trim than selected.
- 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 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.
- Verify that the engine coolant temperature (ECT) has not shifted in value. Allow the engine to run and reach operating temperature. Observe the ECT Sensor parameter with a scan tool and compare the reading to that parameter listed on the K20 Engine Control Module: Scan Tool Information , list. If the reading is not in the range specified in the list, test the resistance of the engine coolant temperature sensor. Refer to Temperature Versus Resistance - Engine Coolant Temperature Sensor , for resistance specifications. Replace the engine coolant temperature sensor if the resistance is not within specification. Refer to Engine Coolant Temperature Sensor Replacement . If the sensor is within the specification, test the engine coolant temperature sensor circuits for high resistance.
- Inspect the mass air flow (MAF) sensor for obstruction, contamination, and damage. Refer to Intake Air Pressure and Temperature Sensor Replacement .
- Inspect the brake system for brake drag.