Test Procedure
WARNING: This page is about a different car, the 2005 GMC Yukon XL, 2005 Chevrolet Suburban, and 2005 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- Test the fuel composition using J 44175 Fuel Composition Tester and J 44175-3 Instruction Manual.
- If water appears in the fuel sample, Clean the fuel system. Refer to Fuel System Cleaning .
- Subtract 50 from the reading on the DMM in order to obtain the percentage of alcohol in the fuel sample. Refer to the examples in the Fuel Composition Test Examples table.
- If the fuel sample contains more than 15 percent ethanol, add fresh, regular gasoline to the vehicle's fuel tank.
- Test the fuel composition.
- If testing shows the ethanol percentage is still more than 15 percent, replace the fuel in the vehicle. Refer to Fuel System Cleaning .
Fuel Composition Test Examples
| - | Frequency (Hz) | Subtract 50 | Ethanol Percent |
|---|---|---|---|
| Example A | 50 Hz | -50 | 0 |
| Example B | 65 Hz | -50 | 15 |
| Example C | 129 Hz | -50 | 79 |