GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 1999 🢒 Isuzu MD Steel Tilt (F Model) 🢒 Body and Accessories 🢒 Instrument Panel, Gauges, and Console 🢒 Fuel Gauge Always Indicates Empty

Fuel Gauge Always Indicates Empty Single Tank

Step

Action

Value(s)

Yes

No

1

Check condition of ignition switch circuit breaker.

Is circuit breaker OPEN?

--

Go to Step 2

Go to Step 3

2

Locate and repair cause of the overload.

Is the repair complete?

--

Go to Step 6

--

3
  1. Disconnect fuel sender or fuel sender and fuel pump connector.
  2. Place ignition switch in RUN.

Does the fuel gauge indicate full?

--

Go to Step 4

Go to Step 5

4

Replace the fuel sender or fuel sender and fuel pump.

Is the repair complete?

--

System OK

--

5

Locate and repair short to ground in CKT 30 (PPL) wire between IP cluster connector C3 terminal 10 and fuel sender or fuel sender and fuel pump connector.

Is the repair complete?

--

System OK

Go to Step 7

6

Replace the circuit breaker.

Is the repair complete?

--

System OK

--

7

Replace the fuel gauge. Refer to Instrument Cluster Replacement .

Is the repair complete?

--

System OK

--

Fuel Gauge Always Indicates Empty Dual Tanks

Step

Action

Value(s)

Yes

No

1
  1. Remove connector at fuel sender and balance pump control module.
  2. Place the ignition switch in RUN.

Does the fuel gauge indicate FULL?

--

Go to Step 5

Go to Step 2

2

Check for a short to ground in CKT30, CKT 386, CKT24 (PPL) between the fuel sender and balance pump control module connector and the IP cluster harness connector C3 terminal 10.

Was a short to ground found?

--

Go to Step 3

Go to Step 4

3

Repair the short to ground in CKT30, CKT 386, CKT24 (PPL) between the fuel sender and balance pump control module and the IP harness connector C3 terminal 10.

Is the repair complete?

--

System OK

--

4

Replace the fuel gauge. Refer to Instrument Cluster Replacement .

Is the repair complete?

--

System OK

--

5
  1. Connect a jumper between terminal C and terminal F at the fuel sender and balance pump control module harness connector.
  2. Visually inspect the fuel sender and fuel level in the Left fuel tank.
  3. Check the fuel gauge.

Does the fuel gauge indicate the approximate fuel level of the Left fuel tank?

--

Go to Step 9

Go to Step 6

6

Check for a short to ground in CKT1936 (DK BLU) between the fuel sender and balance pump control module harness connector and the Left fuel tank harness connector.

Was a short found?

--

Go to Step 7

Go to Step 8

7

Repair the short in CKT1936 (DK BLU) between the fuel sender and balance pump control module and the Left fuel tank.

Is the repair complete?

--

System OK

--

8

Replace the fuel sender and fuel pump assembly.

Is the repair complete?

--

System OK

--

9
  1. Connect a jumper wire between terminal B and terminal F at the fuel sender and balance pump control module.
  2. Visually inspect the fuel sender and fuel level in the Right fuel tank.
  3. Check the fuel gauge.

Does the fuel gauge indicate the approximate fuel level of the Right fuel tank?

--

Go to Step 10

Go to Step 11

10

Replace the fuel sender and balance pump control module

Is the repair complete?

--

System OK

--

11

Check CKT1937 (LT BLU) for an open condition between the fuel sender and balance pump control module harness connector and the Right fuel tank harness connector.

Was an open condition found?

--

Go to Step 12

Go to Step 13

12

Repair the open in CKT1937 (LT BLU) between the fuel sender and balance pump control module harness connector and the Right fuel tank harness connector.

Is the repair complete?

--

System OK

--

13

Replace the fuel sender and fuel pump assembly.

Is the repair complete?

--

System OK

--