The diesel engine fuel filter incorporates a water separator that removes and traps water in the fuel. This water must be drained from the filter at the specified intervals or when the Water In Fuel (WIF) light is on. Place a small container under the filter drain tube (diesel fuel can damage asphalt paving). For 2009 models, with the engine off, rotate the drain valve one turn counter-clockwise. Allow the water and contaminated fuel to drain out. Repeat the procedure until clean fuel flows from the filter drain tube, then place the drain valve in the closed position. For 2010 and later models, turn the drain valve knob 1/4-turn counterclockwise and unscrew the filter housing cover 1/2 turn. Allow the water and contaminated fuel to drain for two minutes, then close the drain valve and tighten the filter housing cover. Remove the container and dispose of the fuel/water mixture properly. If more than a couple of ounces had to be drained to remove any accumulated water, the fuel system may have to be primed for the engine to start. FUEL FILTER REPLACEMENT: At the specified intervals, the fuel filter element (which incorporates a water separator) should be replaced with a new one. Raise the vehicle and support it securely on jack stands. Remove the left front wheel and the fender splash shield. Drain the filter into a container and dispose of the fuel safely. Attach a hose extension to avoid spillage. Loosen the filter slightly to speed draining. For 2009 models, disconnect the Water In Fuel (WIF) harness connector, the drain hose, and extension hose from the drain valve. Use an oil filter wrench to rotate the bottom portion (canister filter) from the fuel filter assembly. Spin the fuel filter by hand from the fuel filter/canister assembly and set it aside. Remove the secondary fuel filter screen from the fuel filter assembly. Release the quick-connect fuel line fitting from the fuel filter assembly. Unscrew the line fitting from the fuel filter assembly and remove the fuel line along with the O-ring and filter screen. Clean the fuel filter screen and replace the O-ring with a new one. Installation is the reverse of removal. Use a new filter cartridge in the fuel filter assembly and a new O-ring in the fuel line. Turn the key to the On position, allowing the fuel pump to prime the system. Repeat this a few times until the engine starts. Run the engine and check for leaks. For 2010 and later models, clean all of the debris from the area of the fuel filter lid. Use a ratchet and socket to remove the fuel filter lid, then discard the O-ring from the canister. Remove the fuel filter element. Wipe out the interior of the canister but don't use any harsh chemicals such as brake cleaner. Install the new filter element. Lubricate the new O-ring with clean engine oil and install it on the canister. Replace the lid and tighten it to the torque. Turn the key to the On position, then briefly turn it to Start. This will allow the fuel pump to run for 25 seconds and should prime the system. If the vehicle doesn't start, repeat the procedure.