GM 19148811
Fuel Gauge Sending Unit

The procedure to replace the Fuel Level Sensor assembly starts with removing the Fuel Tank before disconnecting both the fuel line and evaporative emission (EVAP) line from the sensor unit. The Fuel Level Sensor lock ring wrench (J 45722) together with a long breaker-bar enables the user to unlock the Fuel Level Sensor lock ring while ensuring proper fuel assembly drainage into an approved fire-safe container. Use j 45722 exclusively to avoid damaging the lock ring and do not handle the Fuel Level Sensor assembly by the fuel pipes because this will cause joint damage. Significant force requires the lock ring to release and hammering it with screwdriver types of tools should be avoided. The Fuel Tank requires attachment to stop tank rotation motion. The sensor unit must be removed followed by disposing the seal while cleaning the seal surfaces and checking the lock ring flatness with a feeler gauge at seven points. Lock rings need replacement because warpage measures exceed 0.41 mm (0.016 in). But the lock ring remains usable if it maintains a proper shape without damage. When putting back the Fuel Level Sensor assembly replace the Fuel Level Sensor gasket immediately as it reduces fire risk and make sure the fuel strainer points horizontally toward prevent float arm obstruction. The sensor unit should be installed first before using the j 45722 to tighten the Fuel Level Sensor lock ring clockwise with the designated side facing upward. The evap line should connect together with the fuel line to the sensor unit preceding Fuel Tank installation.

The process of changing the fuel level sensor in 4.8L, 5.3L and 6.0L engines starts with removal of the sending unit followed by disconnection of the fuel pump electrical connector. Before proceeding with replacement you need to eliminate the retaining clip that retains the fuel lever sensor connector while you unplug both the fuel level sensor connector and the fuel lever sensor connector. The next step requires you to remove both clips holding the fuel level sensor electrical connector then detach the sensor. The first step in installation requires you to install the new fuel level sensor before applying the retaining clip. Position the fuel level sensor electrical connector and secure it with the retaining clip meant for the fuel lever sensor electrical connector. Reinstall the sending unit by reattaching the fuel pump electrical connector before finishing the installation.

Begin by removing the sending unit.

Connect the EVAP line and the fuel line to the sending unit before reinstalling the fuel tank.

Connect the wiring pigtail electrical connector to the module cover.

Connect the EVAP line and the fuel line to the sending unit.