Fuel Gage Inaccurate or Inoperative. Cadillac Eldorado 2002

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2002 🢒 Eldorado 🢒 Body and Accessories 🢒 Instrument Panel, Gages, and Console 🢒 Fuel Gage Inaccurate or Inoperative

Diagnostic Aids

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

•	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 readings for the fuel level sensor. The Fuel Level parameter is available on the scan tool in the PCM EVAP data list.

Test Description

The numbers below refer to the step numbers in the diagnostic table.

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

DTCs will be set in the BCM when you perform this diagnostic table.

Step

Action

Value(s)

Yes

Schematic Reference: Instrument Cluster Schematics

Did you perform the Instrument Cluster Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

Disconnect C415.
Connect the J 33431-C Signal Generator and Instrument Panel Tester between the signal circuit and the low reference circuit of the fuel level sensor on the female terminal side of the connector.
Turn the ignition ON, with the engine OFF.

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

Vary the resistance on the J 33431-C from 40-220 ohms.
Refer to Fuel Level Specifications in order to convert from resistance to fuel gage display.

Does the fuel gage display the correct fuel level?

Go to Step 4

Go to Step 3

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

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

Vary the resistance on the J 33431-C from 40-220 ohms.
Refer to Fuel Level Specifications in order to convert from resistance to fuel level.

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 parameter in the PCM EVAP data list.

Does the Fuel Level parameter display the correct fuel level?

Go to Step 11

Go to Step 5

Inspect for the following items:

•	A poor connection at the harness connector of the fuel level sensor

Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

•	A high resistance in the signal circuit of the fuel level sensor or the low reference circuit of the fuel level sensor between the fuel level sensor and C415

Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

•	A misaligned fuel level sender

•	A deformed fuel tank

Did you find and correct the condition?

Go to Step 13

Go to Step 7

Test the signal circuit of the fuel level sensor for a high resistance. Refer to Circuit Testing and to 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 sensor for a high resistance. Refer to Circuit Testing and to 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:

•	The fuel level sensor is stuck, perhaps due to an interference with the fuel strainer

•	The fuel tank contains foreign material, for instance, 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 sensor 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 - 220 ohms

Go to Diagnostic Aids

Go to Step 10

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

Did you find and correct the condition?

Go to Step 13

Go to Step 12

Replace the fuel level sensor. Refer to Fuel Level Sensor Replacement in Engine Controls - 4.6L.

Did you complete the replacement?

Go to Step 13

Important: Program the replacement IPC.