2010 Cadillac CTS Sedan AWD V6-3.6L Page 1412
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* 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)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Verification
1. Ignition ON and fuel cap removed, verify that the Fuel Tank Pressure Sensor parameter is between 1.3-1.7 volts.
瀚慖f not within the specified range, go to the fuel tank pressure sensor section in Circuit/System Testing.
2. Install the fuel cap.
3. With the engine running, the EVAP canister vent solenoid valve open, use a scan tool to command the EVAP canister purge solenoid valve
to 100 percent. The fuel tank vacuum should not increase to more than -15 mmHg (-8 inches H2O).
瀚慖f the fuel tank vacuum is greater than the specified range, go to the restriction section in Circuit/System Testing.
4. Using the scan tool, decrease the canister purge duty cycle from 100 percent to 0 percent. The vacuum should decrease to near zero.
瀚慖f the fuel tank vacuum does not return to zero or appears to decrease too slowly go to the restriction section in Circuit/System Testing.
5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed
from the Freeze Frame/Failure Records data.
Circuit/System Testing
Important: Perform the Circuit/System Verification before proceeding with the Circuit/System Testing.
Restriction
1. With the engine running, the EVAP canister vent solenoid valve open, and the EVAP canister purge solenoid valve commanded to 100
percent, the fuel tank vacuum should not increase to more than -15 mmHg (-8 inches H2O).
瀚慖f the fuel tank vacuum is greater than the specified value, isolate the restriction by disconnecting one component at a time while the
EVAP canister purge solenoid valve is commanded to 100 percent and the vent valve is open.
2. Using the scan tool, decrease the canister purge duty cycle from 100 percent to 0 percent. The vacuum should decrease to near zero.
瀚慖f the fuel tank vacuum does not return to zero, or appears to decrease too slowly, inspect the components in the EVAP vent system for a
restriction.
Fuel Tank Pressure Sensor
1. Ignition OFF, disconnect the harness connector at the fuel tank pressure sensor.
2. Ignition OFF, test for less than 5 ohms between the low reference circuit terminal and ground.
瀚慖f greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the fuel
tank pressure sensor.
Repair Instructions
* Evaporative Emission System Hose/Pipe Replacement (See: Powertrain Management/Emission Control Systems/Evaporative Emissions
System/Evaporative Emissions Hose/Service and Repair)
* Evaporative Emission Canister Vent Solenoid Valve Replacement (See: Powertrain Management/Emission Control Systems/Evaporative
Emissions System/Evaporative Emission Control Canister/Canister Vent Valve/Service and Repair)
* Evaporative Emission Canister Replacement (See: Powertrain Management/Emission Control Systems/Evaporative Emissions
System/Evaporative Emission Control Canister/Service and Repair)
* Fuel Tank Pressure Sensor Replacement (See: Powertrain Management/Computers and Control Systems/Fuel Tank Pressure Sensor/Service
and Repair)
* Control Module References (See: Testing and Inspection/Programming and Relearning)
