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For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 GMC P42 Commercial Chassis 🢒 Body and Accessories 🢒 Instrument Panel, Gauges, and Console 🢒 Fuel Gauge Always Indicates Empty

Fuel Gauge Always Indicates Empty P32/42 Diesel

Step

Action

Value(s)

Yes

No

1
  1. Turn the ignition switch to the RUN position.
  2. Disconnect the fuel level sensor.

Did the fuel gauge move toward FULL?

--

Go to Step 2

Go to Step 3

2

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

Is the repair complete?

--

System OK

--

3

With a test light,backprobe the instrument cluster connector from cavity 16 to B +.

Refer to Using Connector Test Adapters in Wiring Systems.

Did the test light illuminate?

--

Go to Step 4

Go to Step 5

4

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

Is the repair complete?

--

System OK

--

5

Backprobe the instrument cluster with a test light from connector cavity 31 to B+.

Did the test light illuminate?

--

Go to Step 7

Go to Step 6

6

Repair the open in CKT 451 (BLK/WHT) between the instrument cluster connector and G 108.

Is the repair complete?

--

System OK

--

7

Replace the instrument cluster.

Is the repair complete?

--

System OK

--

Fuel Gauge Always Indicates Empty P32/42 Gasoline

Step

Action

Value(s)

Yes

No

1
  1. Ensure that 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.

Does the FUEL gauge continue to indicate EMPTY?

--

Go to Step 2

Go to Step 3

2

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

Is the repair complete?

--

System OK

--

3

With the VCM disconnected and the ignition switch in the RUN position, does the FUEL gauge indicate FULL?

--

Go to Step 4

Go to Step 5

4
  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. Refer to Using Connector Test Adapters in Wiring Systems.

Is the resistance within the specified values?

40 ohms-250 ohms

Go to Step 5

Go to Step 6

5

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

Is the repair complete?

--

System OK

--

6
  1. Disconnect the fuel pump module. Refer to Fuel Sender Assembly Replacement 4.3L, Fuel Level Sensor Replacement 5.7L, Fuel Level Sensor Replacement 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 7

Go to Step 8

7

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

Is the repair complete?

--

System OK

--

8

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

Is the repair complete?

--

System OK

--