2010 Cadillac CTS Sedan AWD V6-3.6L Page 1417
DTCs P0450 and P0451 are Type B DTCs.
Diagnostic Aids
A blocked or clogged EVAP canister vent may set these DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics (LLT) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)Engine Controls Schematics
(LF1) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Fuel System Description (See: Powertrain Management/Computers and Control Systems/Description and Operation/Fuel System Description)
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)
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
Special Tools
* J 41413-SPT High Intensity White Light
* J 41413-VLV EVAP Port Vent Fitting Tool
* J 41413-200 Evaporative Emissions System Tester (EEST)
* J 41413-300 EVAP Cap and Plug Kit
* CH-48096 EVAP Service Port Access Tool
* GE-41415-50 Fuel Tank Cap Adapter
Circuit/System Testing
1. Ignition OFF, remove the fuel fill cap. Connect the GE-41415-50 to the fuel tank filler neck. Connect the J 41413-200 to the GE-41415-50
.
2. Ignition ON, seal the system using the Purge Seal function with a scan tool.
3. Pressurize the EVAP system with nitrogen to 9.33 mm/Hg (5 in. H2O). Compare the scan tool Fuel Tank Pressure Sensor parameter to the J
41413-200 pressure/vacuum gauge. Verify the FTP sensor parameter is within +/-0.9 mmHg (+/-0.5 in.H2O) of the pressure/vacuum gauge.
瀚慖f not within the specified range, replace the FTP sensor.
4. Command the EVAP vent solenoid valve OPEN with a scan tool. Verify the scan tool FTP sensor parameter is -0.9 to +0.9 mmHg (-0.5 to
+0.5 in.H2O).
瀚慖f not within the specified range, replace the FTP sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
Fuel Tank Pressure Sensor Replacement (See: Powertrain Management/Computers and Control Systems/Fuel Tank Pressure Sensor/Service and
Repair)
P0451
DTC P0450 or P0451 (w/LLT)
Diagnostic Instructions
