DE - Testing Notes

DESCRIPTION
The Flexible Fuel (FF) sensor is a capacitive device with a signal processing stage whose frequency varies with the dielectric constant, conductivity and temperature of the fluid medium (methanol-gasoline mixture) in its measuring cell.

In general, as the percentage of methanol in the fuel increases, the output frequency of the FF sensor signal will increase.

For example, a fuel mixture that was determined to be 30% methanol will result in the FF sensor signal output frequency being between 60 and 100 Hz; 60% methanol results in a FF sensor signal output frequency between 90 and 130 Hz.

The Powertrain Control Module (PCM) uses the percent methanol information to calculate the correct air/fuel ratio and spark advance for the vehicle.


REMEMBER
To prevent the replacement of good components, be aware that this test is to be used only on vehicles that have methanol-gasoline fuel mixtures in their fuel systems. If the vehicle under observation has anything other than a methanol-gasoline fuel mixture in its fuel system, then this test procedure should not be used. The following non-Electronic Engine Controls (EEC) areas may be at fault:

- Ignition system

- Fuel system

This Pinpoint Test is intended to diagnose only the following:

- FF sensor

- Harness circuits: FF sensor signal, VPWR and PWR GND

- PCM

NOTE: You should enter this pinpoint test only when you have been directed here from Diagnostic Routines.

WARNING

- Handle methanol-gasoline fuel blends with extreme caution; wear chemical goggles and impervious gloves.

- Do not eat, smoke, or drink when these fuel blends are being handled.

- Flames from methanol or methanol-gasoline blends may be invisible.

- Inhaling vapors from these fuel blends are harmful to your health, handle only in well-ventilated areas.




SAFE FUEL HANDLING PRACTICES: GASOLINE, METHANOL AND METHANOL BLENDS

FIRE

- Report all fires to the appropriate authorities.

- Flames from methanol or methanol-gasoline blends may be invisible.

- Know the locations of portable fire extinguishers, fire blankets, fire alarms and eye/wash shower facilities. Learn how to use them.

- Use a B or AFFF (light water) type FIRE EXTINGUISHER to fight flammable liquid fires.

FIRST AID

- IF SWALLOWED:

- If gasoline has been swallowed, do not induce vomiting. Seek medical attention immediately!

- If methanol or a methanol/gasoline blend has been swallowed, induce vomiting under the direction of a physician or poison control center. Seek medical attention immediately!

- When overcome by vapors move victim to fresh air if safe. If not breathing, give artificial respiration or CPR (Cardiopulmonary Resuscitation) as appropriate. Seek medical attention immediately!

- If splashed in eyes, flush with large amounts of water for 15 minutes. Remove contact lenses, if worn. Seek medical attention.

- If splashed on skin, remove contaminated clothing. Wash skin thoroughly with soap and water.

HEALTH

- All fuels may be harmful or fatal if swallowed.

- Be aware, if swallowed, onset of serious health effects may be delayed 12 to 24 hours.

- Fuels and products containing methanol (e.g. windshield washer fluid) may cause blindness if swallowed.

- All fuel vapors may be harmful by inhalation.

- All fuels are irritating to the eyes and respiratory system.

- Fuels made with gasoline may contain benzene which is a cancer-causing agent.

HANDLING

- Use flammable liquid handling precautions.

- Wear chemical goggles and nitrile gloves (additional protective clothing and equipment may be necessary in some instances).

- Keep flammable liquids in approved labeled closed containers.

- Use in well-ventilated areas and control vapors. Be aware that vapors are not visible, are heavier than air, can travel along the floor, and will settle in lower areas.

- When transferring flammable liquids, bond the receiving container to the source and ground the source to the earth.

- Do not smoke or use heat/spark producing equipment near vapors.

- Do not eat, smoke or drink where these products are handled, processed or stored.

- Never siphon by mouth.

- Wash hands thoroughly after handling any fuel.

SPILLS

- Notify the proper authorities in the event of any spill you have not been trained to clean up.

- Stop, contain, and clean up small spills with an absorbent material.