Fuel heater, fuel filter housing and fuel heater relay – replacement
Warning: Diesel fuel is flammable, so take extra precautions when you work on any part of the fuel system. See the Warning in Fuel transfer pump – check and replacement.
Fuel heater
1. The fuel heater prevents diesel fuel from waxing during cold weather operation. A defective fuel heater can cause wax build-up in the fuel filter/water separator. This clogging effect can make the engine difficult to start and prevent the engine from revving up. This condition can also cause a fog-like blue or white exhaust. If the heater doesn’t operate in a cold climate, the engine might not operate at all because of fuel waxing.
2009 models
Note: The fuel heater is located on the fuel filter/water separator housing.
2. Drain the water and fuel contaminants from the fuel filter assembly (see Tune-up and routine maintenance).
3. Disconnect the fuel heater element connector (see illustration).
8.3 Fuel filter assembly details
1 WIF harness connector
2. WIF sensor
3. Drain valve
4. Drain tube
5. Fuel filter canister
6. Fuel line connector
7. Fuel line
8. Filter screen
9. Fuel heater element connector
4. Remove the two fuel heater element mounting screws.
5. Remove the fuel heater element from the fuel filter assembly.
6. Replace the 0-ring with a new one.
7. Installation is the reverse of removal.
2010 and later models
8. The heater on 2010 and later models is an integral part of the fuel filter housing assembly. It can’t be replaced separately; go to Step 9 for the filter housing replacement procedure.
Fuel filter housing
9. Drain the water and fuel contaminants from the fuel filter assembly (see Tune-up and routine maintenance).
10. If necessary, detach the engine oil dipstick tube from the filter housing.
11. Disconnect the wiring from the filter assembly.
12. Disconnect all of the fuel lines from the filter assembly.
13. Remove the mounting bolts and remove the filter unit from the engine.
14. Thoroughly clean all mounting surfaces, then install the housing and the mounting bolts and tighten them to the torque listed in this Chapter’s Specifications.
15. Replace the banjo bolt washers with new ones. The remainder of installation is the reverse of removal.
Fuel heater relay
16. There is no serviceable fuel heater relay; it is an integral part of the underhood fuse/ relay box, which the manufacturer calls the Totally Integrated Power Module (TIPM).