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Home >> Cadillac >> 2002 >> Escalade EXT >> Repair and Diagnosis >> External Pages >> Different car >> Section 341 (Engine Controls - System & Component Testing - 3.4L) >> Fuel Systems >> Alcohol/Contaminants-In-Fuel Diagnosis With Special Tool >> Test Procedure
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Test Procedure

WARNING: This page is about a different car, the 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, 2003 Chevrolet Monte Carlo, and 2003 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.
  1. Test the fuel composition using Fuel Composition Tester (J 44175) and Instruction Manual (J44175-3), or equivalents.
  2. If water appears in the fuel sample, clean the fuel system. Go to FUEL SYSTEM CLEANING  and/or replace the fuel filter as necessary.
  3. Subtract 50 from the reading on the DMM to obtain the percentage of alcohol in the fuel sample. See the examples in the FUEL COMPOSITION TEST EXAMPLES  table.
  4. If the fuel sample contains more than 15 percent ethanol, add fresh, regular gasoline to the vehicle's fuel tank.
  5. Test the fuel composition.
  6. If testing shows the ethanol percentage is still more than 15 percent, replace the fuel in the vehicle. Go to FUEL SYSTEM CLEANING .
FUEL COMPOSITION TEST EXAMPLES

Example Frequency - Hz Subtract 50 Ethanol Percent
A 50 -50 0
B 65 -50 15
C 129 -50 79