Fuel Gage Inaccurate or Inoperative. Chevrolet Impala 2000

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2000 🢒 Impala 🢒 Body and Accessories 🢒 Instrument Panel, Gauges, and Console 🢒 Fuel Gage Inaccurate or Inoperative

Diagnostic Aids

•	Ensure that the fuel level is in the same range as the customer concern.

•	An access panel to the fuel sender assembly is in the trunk.

•	For intermittent diagnosis, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

•	Refer to Fuel Level Specifications in order to verify the correct fuel level sender readings. The fuel level percent parameter is available on the scan tool in the PCM EVAP data list.

Test Description

The number(s) below refer to the step number(s) in the diagnostic table.

This step tests for a high resistance in the signal circuit and the low reference circuit of the fuel level sender.

DTCs will be set when you perform this diagnostic table.

Step

Action

Value(s)

Yes

Did you perform the Instrument Cluster Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

Disconnect the fuel level sender.
Connect the J 33431-C Signal Generator and Instrument Panel Tester between the signal circuit of the fuel level sender and the low reference circuit of the fuel level sender.
Turn ON the ignition, with the engine OFF.

Important: Verify the J 33431-C resistance settings with a DMM.

Vary the resistance on the J 33431-C from 40-250 ohms.
Refer to Fuel Level Specifications in order to convert from resistance to fuel gauge display.

Does the fuel gauge display the correct fuel level?

Go to Step 4

Go to Step 3

Install a scan tool.
Turn ON the ignition, with the engine OFF.

Important: Verify the J 33431-C resistance settings with a DMM.

Vary the resistance on the J 33431-C from 40-250 ohms.
Refer to Fuel Level Specifications in order to convert from resistance to fuel level percentage.

Important: Turn OFF the ignition momentarily between the resistance settings in order to quickly update the scan tool display.

With the scan tool, observe the fuel level percent parameter in the PCM EVAP data list.

Does the scan tool display the correct fuel level percentage?

Go to Step 11

Go to Step 5

Inspect for the following items:

•	A poor connection at the harness connector of the fuel level sender. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

•	A deformed fuel tank.

•	A misaligned fuel level sender.

Did you find and correct the condition?

Go to Step 13

Go to Step 7

Test the signal circuit of the fuel level sender for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 6

Test the low reference circuit of the fuel level sender for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 9

Remove the fuel level sender.
Inspect for the following items:

•	A stuck fuel level sender (i.e. the fuel strainer interfering with the sender float arm).

•	Foreign material in the gas tank (ice).

Did you find and correct the condition?

Go to Step 13

Go to Step 8

With the J 39200 DMM, measure the resistance of the fuel level sender while moving the float arm.
Observe both the analog and digital displays on the DMM.

Does the resistance change smoothly across the specified range?

40-250 ohms

Go to Diagnostic Aids

Go to Step 10

Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 12

Replace the fuel level sender. Refer to Fuel Level Sensor Replacement (3.4L) or Fuel Level Sensor Replacement (3.8L) in Engine Controls.

Did you complete the replacement?

Go to Step 13

Replace the IPC. Refer to Instrument Cluster Replacement .