Test Procedure
- HC1 CHECK THE SYSTEM INTEGRITY
- Visually inspect the complete fuel delivery system for damage and leakage.
- Check the following:
- Verify the fuse integrity.
- Verify the battery is fully charged.
- Verify the fuel level, grade, and quality is sufficient to support normal operation of the engine.
Is a concern present?
Yes No REPAIR as necessary.
Clear the PCM DTCs. REPEAT the self-test.GO to HC2. - HC2 CHECK THE FUEL PRESSURE
- Ignition OFF.
- Relieve the fuel pressure. Refer to the Fuel System article for the Fuel System Pressure Release procedure.
- Mechanical fuel pressure gauge connected.
- Ignition ON, engine OFF.
- Pressurize the fuel system. Refer to the Fuel System article for the Fuel System Pressure Release procedure to pressurize the fuel system.
- Cycle the ignition several times to charge the fuel system.
- Compare the fuel pressure reading to the Fuel System Specification Chart.
Is the fuel pressure within range?
Yes No GO to HC5. GO to HC3. - HC3 CHECK THE FUEL PUMP GROUND CIRCUIT FOR AN OPEN NOTE: Refer to the OEM Electrical Wiring Diagram Introduction for schematic and connector information.
- Ignition OFF.
- FP Assembly connector disconnected.
- Measure the resistance between:
(+) FP Assembly Connector, Harness Side (-) FPRTN - Pin 4 Ground
Is the resistance less than 5 ohms?
Yes No GO to HC4. REPAIR the open circuit. Clear the PCM DTCs.
REPEAT the self-test. - HC4 CHECK THE FUEL PUMP POWER CIRCUIT FOR AN OPEN NOTE: During output state control, the fuel pump stays commanded ON for only about 2 seconds. Be aware that output state control turns the fuel pump OFF after a calibrated time. If this happens, command the outputs ON again to continue testing.
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) FP Assembly Connector, Harness Side (-) Vehicle Battery FPPWR - Pin 5 Negative terminal - Access the PCM and control the FP (MODE) PID.
- Command the fuel pump ON.
Is the voltage greater than 10.5 V?
Yes No For vehicles that do not start, GO to HC10.
For all others, GO to HC7.GO to PINPOINT TEST KC . - HC5 CHECK THE SEPARATION LEVEL OF THE ETHANOL/WATER MIXTURE AND GASOLINE IN THE FUEL NOTE: This step requires the use of a locally obtained 200 ml beaker and a 25 ml graduated cylinder.NOTE: After approximately 3 minutes of standing, the ethanol and water mixes together and settles to the bottom of the 25 ml graduated cylinder. The gasoline rises to the top.
- Fill the 200 ml beaker with 5 ml of clean water.
- Use the pressure relief valve on the mechanical fuel gauge to drain 22 ml of fuel into an approved clean container.
- Pour 20 ml of fuel from the approved clean container into the 25 ml graduated cylinder.
- Add enough water from the 200 ml beaker to the 25 ml graduated cylinder to bring the total volume of liquid to 24 ml.
- Insert a stopper plug in the opening of the 25 ml graduated cylinder.
- Firmly hold the stopper in place and shake the 25 ml graduated cylinder to mix the water and fuel.
- Allow the liquid to stand and separate for approximately 3 minutes.
- Record the separation level from the 25 ml graduated cylinder where the ethanol/water mixture and gasoline meet.
Did the ethanol/water mixture and gasoline separate?
Yes No GO to HC6. The ethanol/water mixture separates from the gasoline. If the fuel does not appear to separate, then the fuel is either 100% ethanol or a mixture of ethanol and water. REPLACE the contaminated fuel.
Clear the PCM DTCs. REPEAT the self-test. - HC6 CALCULATE THE PERCENTAGE OF ETHANOL IN THE FUEL NOTE: Use the illustration as an example for calculating the percentage of ethanol in the following steps. If the separation level is at 14 ml the calculation becomes; 14 minus 4, then multiply by 5 to equal 50. The percentage of ethanol in the fuel is 50%.
- Ignition OFF.
- Take the recorded separation level from the previous step and subtract the amount of water added.
- Multiply the new value by 5. This new value is the percentage of ethanol in the fuel.
Item Number Description 1 Stopper 2 Gasoline 3 Separation Point at 14 ml 4 Ethanol/Water Mixture - Record the calculated percentage of ethanol in the fuel.
Is the calculated percentage of ethanol in the fuel less than 25%?
Yes No GO to HC7. REPAIR as necessary. ADVISE the customer of the correct fuel type required for this vehicle.
REFER to the Owner's Literature for additional information.
Clear the PCM DTCs. REPEAT the self-test. - HC7 CHECK THE FUEL PRESSURE LEAKDOWN NOTE: When the fuel pump is commanded OFF, the fuel pressure may substantially decrease and then stabilize.NOTE: During output state control, the fuel pump stays commanded ON only for approximately 2 seconds.
- Mechanical fuel pressure gauge connected.
- Ignition ON, engine OFF.
- Access the PCM and control the FP (MODE) PID.
- Run the fuel pump to obtain maximum fuel pressure.
- Command the fuel pump off.
- Allow the fuel pressure to stabilize.
- Record the stabilized reading.
- Monitor the fuel pressure for 1 minute.
Does the fuel pressure remain within 34 kPa (5 psi) of the recorded reading after 1 minute?
Yes No GO to HC9. GO to HC8. - HC8 CARRY OUT THE POWER BALANCE TEST NOTE: The IDS test referenced in this step may not be available on all vehicles. Follow the YES answer if the IDS test is not available.
- Carry out the Power Balance Test. Refer to the instruction manual provided by the scan tool manufacturer.
Does the test pass?
Yes No GO to HC9. INSTALL a new fuel injector as necessary. REFER to the Fuel Charging and Controls article.
RESET the keep alive memory (KAM). REFER to RESETTING THE KEEP ALIVE MEMORY (KAM) . REPEAT the self-test. - HC9 MONITOR THE FUEL PRESSURE WHILE ROAD TESTING THE VEHICLE NOTE: Some concerns may only be present during certain fuel level conditions. Determine the fuel level at the time of the concern. Access the information from the customer information worksheet and the customer.
- Ignition OFF.
- Securely route the mechanical gauge so that the gauge is viewable while road testing the vehicle.
- Ignition ON, engine running.
- Engine at normal operating temperature.
- Monitor the mechanical gauge.
- From a stop, accelerate to 89 km/h (55 mph) at full throttle. Repeat this 3 times.
Is the fuel pressure always greater than 352 kPa (51 psi)?
Yes No For misfire DTC diagnosis, GO to HD11.
For DTCs P0171 or P2195. GO to H13.
For the fuel pressure leakdown concern, INSTALL a new FP assembly. REFER to the Fuel Tank and Fuel Lines article.
For all others, RETURN to SYMPTOM CHARTS for further direction.GO to HC10. - HC10 CHECK THE FUEL SUPPLY LINE FOR RESTRICTION NOTE: Observe the warnings, cautions, and notes at the beginning of this pinpoint test.
- Ignition OFF.
- Disconnect the fuel supply line at the fuel rail.
- Disconnect the fuel supply line at the fuel pump.
- Check the fuel supply line for restriction.
- Apply 21 to 34 kPa (3 to 5 psi) air pressure to the fuel supply line.
Does air flow freely through the line?
Yes No INSTALL a new FP assembly. REFER to the Fuel Tank and Fuel Lines article.
Clear the PCM DTCs. REPEAT the self-test.REPAIR the cause of the restriction.
Clear the PCM DTCs. REPEAT the self-test.