When an E85 compatible vehicle is built, an engine control module (ECM) or powertrain control module (PCM) replaced, or when the learned alcohol content has been reset with a scan tool, the fuel system will need to contain ASTM gasoline with 15 percent or less ethanol content. If the fuel in the fuel system needs to be drained and replaced with ASTM gasoline, the engine will need to run at operating temperature and consume at least 1 liter (0.3 gallon) of fuel before the system will recognize the correct alcohol content. Either ASTM gasoline or ASTM E85 fuel can then be used. In order that the ECM/PCM recognizes a proper next fuel fill, the amount must be 11 liters (3 gallons) or more, and the ethanol content must be between 0-85 percent.

Scan Tool Reference

Control Module References for scan tool information

Special Tools

1. Observe the Fuel Composition Learn parameter using the scan tool. The Fuel Composition Learn parameter should display Inactive.

Note: 

•	The key needs to be turned OFF for at least 30 seconds after the parameter displays Inactive to properly store the ethanol learned value in the ECM/PCM memory.

•	The vehicle may need to be driven more than 11 km (7 mi) with the engine at operating temperature.

⇒	If the Fuel Composition Learn parameter displays Active, drive the vehicle until the Fuel Composition Learn parameter displays Inactive.

2. Record the ECM/PCM estimated value of the ethanol content using a scan tool.
3. Record the actual measured percentage of ethanol content using the J 44175 Tester or J 44175-A Tester . The ECM/PCM estimated value should be within 15 percent of the ethanol content measured with the J 44175 Tester .

⇒	If the ECM/PCM estimated value is not within 15 percent of the ethanol content measured with the J44175 Tester continue with Circuit/System Testing.

1. Use the scan tool to reset the Fuel Alcohol Content parameter to 3 percent.
2. Use the scan tool to reset the fuel trim values.

1. Perform a complete key cycle, key ON, engine OFF, in order to ensure that the ECM/PCM recognizes a refueling event.

Note: It may be necessary to partially drain the fuel tank.

2. Key OFF, add at least 11 liters (3 gallons) of non-blended gasoline to the fuel tank.
3. Use the scan tool to reset the Fuel Alcohol Content parameter to 3 percent.

Note: In order to ensure the non-blended gasoline has reached the fuel injectors, the vehicle may need to be driven more than 11 km (7 mi) with the engine at operating temperature.

4. Drive the vehicle until the Fuel Composition Learn parameter displays Inactive.
5. Use the scan tool to reset the fuel trim values.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Fuel System Cleaning