1. Turn the ignition switch to the RUN position.
2. Disconnect the fuel level sensor.
3. Connect a fused jumper wire from fuel level sensor connector, cavity A to ground.

Refer to Using Fused Jumper Wires in Wiring Systems.

Did the fuel gauge move toward EMPTY?

--

Go to Step 2

Go to Step 5

Inspect CKT 150 (BLK) for an open condition between the fuel level sensor connector, cavity D and G 300 (P32), or G 400 (P42).

Was there an open in CKT 150 to ground?

--

Go to Step 3

Go to Step 4

Repair the open in CKT 150 (BLK) between the fuel level sensor connector and G 300 (P32), or G 400 (P42).

Is the repair complete?

--

System OK

--

Replace the fuel level sensor. Refer to Fuel Sender Assembly Replacement in Engine Controls.

Is the repair complete?

--

System OK

--

1. Remove the fused jumper wire from the fuel level sensor connector.
2. With a fused jumper wire, backprobe the instrument cluster connector from cavity 16 to ground.

Refer to Using Connector Test Adapters in Wiring Systems.

Did the fuel gauge move toward EMPTY?

--

Go to Step 6

Go to Step 7

Repair the open in CKT 30 (PPL) between the instrument cluster connector and the fuel level sensor connector.

Is the repair complete?

--

System OK

--

Replace the instrument cluster.

Is the repair complete?

--

System OK

--

1. Ensure the ignition switch is in the OFF position.
2. Disconnect the vehicle control module (VCM) connector C 1.
3. Turn the ignition switch to the RUN position.
4. Use a J 39200 DMM to measure the voltage from the VCM connector C 1, cavity 9 to ground. Refer to Using Connector Test Adapters in Wiring Systems.

Is the voltage less than the specified value?

10.0 V

Go to Step 2

Go to Step 3

Locate and repair the open or short to ground in CKT 30 (PPL) between the VCM and the instrument cluster connector, cavity 16.

Is the repair complete?

--

System OK

--

1. Turn the ignition switch to the OFF position.
2. Install a fused jumper wire from the VCM connector C 1, cavity 9 to ground. Refer to Using Fused Jumper Wires in Wiring Systems.
3. Turn the ignition switch to the RUN position.

Does the FUEL gauge continue to indicate FULL?

--

Go to Step 4

Go to Step 6

1. Turn the ignition switch to the OFF position.
2. Disconnect the instrument cluster.
3. Use a J 39200 DMM to measure the resistance between the instrument cluster connector, cavity 16 and the VCM connector C 1, cavity 9.

Is the resistance greater than the specifed value?

1.0 ohms

Go to Step 5

Go to Step 10

Locate and repair the open in CKT 30 (PPL) between the instrument cluster connector and the VCM connector C 1.

Is the repair complete?

--

System OK

--

1. Turn the ignition switch to the OFF position.
2. Disconnect the VCM connector C 3.
3. Use a J 39200 DMM to measure the resistance between cavity 13 and cavity 19 of the VCM connector C 3.

Is the resistance within the specified values?

40 ohms-250 ohms

Go to Step 7

Go to Step 8

Replace the VCM. Refer to VCM Replacement/Programming 4.3L, VCM Replacement/Programming 5.7L, VCM Replacement/Programming 7.4L in Engine Controls.

Is the repair complete?

--

System OK

--

1. Disconnect the fuel pump module.
2. Use a J 39200 DMM to measure the resistance betweeen cavity A and cavity D of the fuel pump module.

Is the resistance within the specified values?

40 ohms-250 ohms

Go to Step 9

Go to Step 11

Locate and repair the open in CKT 1589 (PPL) or CKT 470 (BLK) between the fuel pump module and the VCM.

Is the repair complete?

--

System OK

--

Replace the instrument cluster.

Is the repair complete?

--

System OK

--

Replace the fuel pump module. Refer to Fuel Sender Assembly Replacement 4.3L, or Fuel Level Sensor Replacement 5.7L and 7.4L in Engine Controls.

Is the repair complete?

--

System OK

--