1. Disconnect the fuel level sensor.
2. Turn the ignition switch to the RUN position.
3. Connect one lead of J 33431-C to the fuel level sensor connector, cavity A and the other lead to ground.
4. Adjust the resistance dial to 0 ohms.
5. Slowly move the resistance dial to 90 ohms.

Did the instrument cluster fuel gauge indicate EMPTY and then move until indicating FULL?

0 ohms-90 ohms

Go to Step 2

Go to Step 3

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

Is the repair complete?

--

System OK

--

1. Disconnect the J 33431-B signal generator.
2. Disconnect the instrument cluster connector.
3. Use a J 39200 DMM to measure the resistance between the instrument cluster connector, cavity 16 and the fuel level sensor connector, cavity A.

Is the resistance greater than the specified value?

5.0 ohms

Go to Step 4

Go to Step 5

Repair the high resistance in CKT 30 (PPL) between 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 that the ignition switch is in the OFF position.
2. Disconnect the vehicle control module (VCM) connector C 1.
3. Connect one lead of a J 33431-C Signal Generator to the VCM connector C 1, cavity 9 and the other lead to ground.
4. Turn the ignition switch to the RUN position.
5. Place the signal generator controls at 0 ohms and slowly turn the contol to 90 ohms while observing the FUEL gauge.

Did the FUEL gauge begin at an EMPTY indication and then gradually move to a FULL indication?

0 ohms-90 ohms

Go to Step 3

Go to Step 2

Replace the instrument cluster.

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 4

1. Disconnect the fuel pump module. Refer to Fuel Sender Assembly Replacement 4.3L, or Fuel Level Sensor Replacement for 5.7L and 7.4L in Engine Controls.
2. Use a J 39200 DMM to measure the resistance between cavity A and cavity D of the fuel pump module.

Is the resistance within the specified values?

40 ohms-250 ohms

Go to Step 5

Go to Step 6

1. Change the amount of fuel in the fuel tank by adding or removing some fuel.
2. Use a J 39200 DMM to measure the resistance between cavity A and cavity D of the fuel pump module.
3. Observe the resistance indicated on the J 39200 DMM.

Did the resistance observed on the J 39200 DMM change in relation to the amount of fuel that was added or removed in the fuel tank?

--

System OK

Go to Step 6

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

Is the repair complete?

--

System OK

--

1. Change the amount of fuel in the fuel tank by adding or removing some fuel.
2. Use a J 39200 DMM to measure the resistance between cavity 13 and cavity 19 of the VCM connector C 3.
3. Observe the resistance indicated on the J 39200 DMM.

Did the resistance observed on the J 39200 change in relation to the amount of fuel that was added or removed in the fuel tank?

--

Go to Step 10

Go to Step 6

Inspect CKT 1589 (PPL) and CKT 470 (BLK) for an open or a short to ground.

Did you find an open or a short to ground?

--

Go to Step 9

Go to Step 10

Repair the open or short to ground in CKT 1589 (PPL) or CKT 470 (BLK) between the fuel pump module and the VCM.

Is the repair complete?

--

System OK

--

Replace the VCM. Refer to VCM Replacement/Programming , VCM Replacement/Programming , or VCM Replacement/Programming in Engine Controls.

Is the repair complete?

--

System OK

--