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Home >> Cadillac >> 2006 >> Escalade AWD >> Repair and Diagnosis >> Accessories & Equipment >> Gauges & Instrument Panels >> Instrument Panel System Displays, Gauges And Console >> Diagnostic Information and Procedures >> Fuel Gage Inaccurate or Inoperative (Dual Tanks) >> Test Description

Test Description

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

  1. 3:  This step tests for high resistance in the signal circuits and the low reference circuit of the fuel level senders.
  2. 15:  DTCs will be set in the PCM when you perform this diagnostic table.
Fuel Gage Inaccurate or Inoperative (Dual Tanks)

Step Action Values Yes No
Schematic Reference: Instrument Cluster Schematics 
Connector End View Reference: Master Electrical Component List in Wiring Systems
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2
  1. Disconnect C152.
  2. Connect a jumper wire between the signal circuit of the primary fuel level sender and the signal circuit of the secondary fuel level sender, male terminal side.
  3. Connect the J 33431-C  Signal Generator and Instrument Panel Tester between the signal circuits of the fuel level senders and the low reference circuit of the fuel level senders, male terminal side. See Special Tools .
  4. Turn ON the ignition, with the engine OFF.
    5. IMPORTANT: Verify the J 33431-C  resistance settings with a DMM. See Special Tools .
  5. Vary the resistance on the J 33431-C  from 40-250 ohms. See Special Tools .
  6. 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 5  Go to Step 3 
3 
  1. Install the scan tool.
  2. Turn ON the ignition, with the engine OFF.
    3. IMPORTANT: Verify the J 33431-C  resistance settings with a DMM. See Special Tools .
  3. Vary the resistance on the J 33431-C  from 40-250 ohms. See Special Tools .
  4. Refer to Fuel Level Specifications  in order to convert from resistance to fuel level percent.
    5. IMPORTANT: Turn OFF the ignition momentarily between the resistance settings in order to quickly update the scan tool display.
  5. With the scan tool, observe the Fuel Tank Level Remaining % parameter in the powertrain control module (PCM) Enhanced evaporative emission (EVAP) Data list.
Does the scan tool display the correct fuel level percent?		 - Go to Step 4  Go to Step 6 
4 With the scan tool, perform the Displays Test in the instrument panel cluster (IPC) scan tool Output Controls.
Does the gage move from 0 to its maximum value and back to 0 when you perform the Displays Test?		 - Go to Step 5  Go to Step 10 
5 Inspect for the following items:
  • A poor connection at the harness connectors of the fuel level senders-Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
  • A high resistance in the signal circuits or the low reference circuit between the fuel level senders and C152
  • A misaligned primary or secondary fuel level sender
  • A deformed primary or secondary fuel tank

Did you find and correct the condition?		 - Go to Step 15  Go to Step 8 
6 Test the signal circuits of the fuel level senders for a high resistance between C152 and the PCM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 15  Go to Step 7 
7 Test the low reference circuit of the fuel level senders for a high resistance between C152 and the PCM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 15  Go to Step 11 
8
  1. Remove the fuel level senders.
  2. 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 fuel tanks, ice
Did you find and correct the condition?		 - Go to Step 15  Go to Step 9 
9
  1. With the DMM, measure the resistance of the fuel level senders while moving the float arm.
  2. Observe both the analog and digital displays on the DMM.
Does the resistance change smoothly across the specified range?		 40-250 Ω Go to Diagnostic Aids Go to Step 12 
10 Inspect for poor connections at the harness connector of the IPC. 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 15  Go to Step 13 
11 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 15  Go to Step 14 
12 Replace the primary or the secondary fuel level sender. Refer to the following procedures:
Did you complete the replacement?		 - Go to Step 15  -
13 Replace the instrument panel cluster (IPC). Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
Did you complete the replacement?		 - Go to Step 15  -
14 Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
Did you complete the replacement?		 - Go to Step 15  -
15 
  1. Use the scan tool in order to clear the PCM DTCs.
  2. Operate the system in order to verify the repair.
Did you correct the condition?		 - System OK Go to Step 2 
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