K 2500 Suburban 4WD V8-6.0L VIN U (2001)
9. Pour the fuel sample from the beaker (1) into the J 44175, until the level of the fuel is at the top of each fuel test port (2).
10. Observe the diagnostic LEDs on the fuel composition tester.
If the red fuel diagnostic LED is illuminated, a fuel contamination condition exists. Refer to Fuel System Cleaning. See: Service and Repair
11. Measure the output frequency of the fuel composition tester.
Alcohol/Contaminants-in-Fuel Diagnosis (With Special Tool)
12. Subtract 50 from the reading on the DMM to obtain the percentage of alcohol in the fuel sample. Refer to the examples in the table.
13. If the fuel sample contains more than 15 percent ethanol, replace the fuel in the vehicle.
