2010 Cadillac CTS Sedan AWD V6-3.6L Page 1439
senses a high signal voltage. The ECM uses the signal circuits of the primary fuel level sender and the secondary fuel level sender in order to
calculate the percentage of remaining fuel in the tank. The ECM sends the fuel level percentage via serial data circuit to the instrument cluster in
order to control the fuel gauge.
Conditions for Running the DTC
* The engine is running.
* The system voltage is between 10-18 V.
* Fuel level state is stable.
Conditions for Setting the DTC
* The primary fuel level signal is about 3.2 V.
* The above condition is present for about 60 seconds.
Action Taken When the DTC Sets
* The fuel gauge defaults to empty.
* The low fuel indicator illuminates.
* The ECM records the operating conditions at the time that the diagnostic test fails. The ECM displays the failure information in the Failure
Records on the scan tool.
Conditions for Clearing the DTC
* The DTC becomes history when the conditions for setting the DTC are no longer present.
* The history DTC clears after 40 malfunction-free warm-up cycles.
Reference Information
Schematic Reference
Instrument Cluster Schematics (See: Diagrams/Electrical Diagrams/Instrument Panel, Gauges and Warning Indicators/System Diagram/Instrument
Cluster Schematics)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Fuel Gauge Description and Operation (See: Instrument Panel, Gauges and Warning Indicators/Description and Operation/Fuel Gauge)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Verification
Ignition ON, observe the scan tool Fuel Level Sensor parameter. The reading should be between 0.9-2.5 V.
Circuit/System Testing
Note: If equipped, the following tests can be performed at an inline connector. See schematics for the corresponding terminals to test at.
1. Ignition OFF, disconnect the harness connector at the primary fuel level sensor.
2. Ignition OFF, test for less than 1 ohm between the low reference circuit terminal 4 and ground.
瀚慖f greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests
normal, replace the ECM.
3. Ignition ON, install a 3 A fused jumper between the primary signal circuit terminal 1 and the low reference circuit terminal 4. Verify the scan
tool Fuel Level Sensor Left Tank parameter is less than 0.4 V.
瀚慖f greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal,
