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Home >> Cadillac >> 2007 >> CTS V >> Repair and Diagnosis >> Accessories & Equipment >> Gauges & Instrument Panels >> Instrument Panel System Displays And Gauges >> Diagnostic Information and Procedures >> DTC P2068 (2.8L and 3.6L) >> Test Description

Test Description

The number below refers to the step number on the diagnostic table.

  1. 3:  This step tests for the proper operation of the circuit in the low voltage range.
DTC P2068 (2.8L and 3.6L)

Step Action Value(s) Yes No
Schematic Reference: Instrument Cluster Schematics 
Connector End View Reference: Master Electrical Component List
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Fuel Level Sensor Left parameter in the engine control module (ECM) EVAP data list.
Does the scan tool indicate that the Fuel Level Sensor Left parameter is greater than the specified value?		 4.0 V Go to Step 3  Go to Diagnostic Aids In This Test
3 
  1. Turn OFF the ignition.
  2. Disconnect C420.
  3. Connect a 3-amp fused jumper wire between the signal circuit of the secondary fuel level sensor and the low reference circuit of the secondary fuel level sensor on the male terminal side of the connector.
  4. Turn ON the ignition, with the engine OFF.
  5. With a scan tool, observe the Fuel Level Sensor Left parameter.
Does the scan tool indicate that the Fuel Level Sensor Left parameter is less than the specified value?		 0.35 V Go to Step 6  Go to Step 4 
4 Test the signal circuit of the secondary fuel level sensor for the following:
  • An open
  • High resistance
  • A short to voltage

Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 12  Go to Step 5 
5 Test the low reference circuit of the secondary fuel level sensor for an open or for a high resistance. Refer Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 12  Go to Step 9 
6 Test the signal circuit of the secondary fuel level sensor for the following:
  • An open
  • High resistance
  • A short to voltage between C420 and the secondary fuel level sensor

Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 12  Go to Step 7 
7 Test the low reference circuit of the secondary fuel level sensor for an open or for a high resistance between C420 and the secondary fuel level sensor. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 12  Go to Step 8 
8 Inspect for poor connections at the harness connector of the secondary fuel level sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 - Go to Step 12  Go to Step 10 
9 Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 - Go to Step 12  Go to Step 11 
10 Replace the secondary fuel tank module. Refer Secondary Fuel Tank Module Replacement for the 2.8L engine or Secondary Fuel Tank Module Replacement for the 3.6L engine.
Did you complete the replacement?		 - Go to Step 12  -
11 Replace the ECM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 - Go to Step 12  -
12
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?		 - Go to Step 2  System OK
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