Component Tests and General Diagnostics
DIAGNOSTIC PROCEDURESSufficient Clean Fuel
NOTICE: Only use ultra low sulfur diesel fuel that is 20% or less biodiesel with this vehicle. Use of any other fuel type may damage the vehicle or cause an emission concern. Refer to the Owner's Literature for more information.
Recommended Procedure:
Observe the water in fuel (WIF) indicator. If the WIF indicator is illuminated, the fuel may be contaminated with water.
Open the drain valve integrated in the fuel conditioning module and drain fuel into a clear 0.95 liter (1 quart) container. Close the drain valve.
Inspect the fuel in the container. The fuel should be clear of water or contaminants. Dyed red or blue fuel indicates off-highway fuel.
Inspect the fuel for waxing or gelling. Waxing or gelling in the fuel may clog fuel filters, the fuel pump, cause restrictions in the fuel, or cause low fuel pressure.
Sediment and water in the fuel sample may indicate the fuel conditioning module has not been drained recently or fuel filter maintenance may be required. A second sample may be required to determine fuel quality.
Cloudy fuel indicates the fuel may not be a suitable grade for cold temperatures.
Excessive water or contaminants may indicate the tank and fuel system may need to be flushed and cleaned.
Aeration in fuel may indicate a leak in the low pressure fuel supply line between the fuel tank and the fuel conditioning module. Aeration can also be caused by a loose fuel conditioning module filter bowl. Make sure the filter bowl is correctly installed.
Possible Causes:
- No fuel in the tank
- Fuel gelled
- Fuel quality
- Aeration
- Biodiesel-water separation, seal degradation, corrosion
- Restricted fuel filters
- Fuel supply line broken or crimped
- Corrosion to fuel system components
- Pickup tube screen in tank restricted
Tools Required:
Clear container 0.95 L (1 quart)