GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

DEFINITION: This table is used to diagnose an inoperative fuel gauge.

1

Was the Instrument Cluster Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2

  1. Install a scan tool.
  2. Select Special Functions from the Instrument Cluster menu.
  3. Select the Fuel Gauge test from the Special Functions menu.
  4. Command the fuel gauge to sweep entirely in either direction.

Does the fuel gauge respond when commanded?

--

Go to Step 3

Go to Step 4

3

  1. Disconnect connector C400.
  2. Turn ON the ignition, with the engine OFF.
  3. Measure the voltage at terminal C of connector C400 (CKT PF12 BLU/BLK).

Does the voltage measure near the specified value?

12 V

Go to Step 5

Go to Step 6

4

Inspect for poor connections at the instrument cluster connector. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition.

--

Go to Step 2

Go to Step 8

5

Test the fuel sender ground circuit for an open or high resistance. Refer to Testing for Continuity in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 7

Go to Step 9

6

Test the fuel level circuit for an open or high resistance. Refer to Testing for Continuity in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 7

Go to Step 10

7

  1. Connect all connectors and components that were removed in previous steps.
  2. Verify that the fuel gauge operates properly.

Does the fuel gauge operate properly?

--

System OK

Go to Step 2

8

Replace the instrument cluster.

Did you complete the replacement?

--

Go to Step 7

--

9

  1. Inspect for poor connections at connector C400 terminals D and G.
  2. Inspect for poor connections at the fuel sender connector terminals C and D. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 7

Go to Step 11

10

Inspect for poor connections at the instrument cluster connector. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition.

--

Go to Step 3

Go to Step 8

11

Replace the fuel sender assembly.

Did you complete the replacement?

--

Go to Step 7

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