2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1357
circuit is normal.
4. Ignition ON, use a scan tool to command the EVAP vent solenoid valve ON and OFF. The test lamp should turn ON and OFF.
瀚慖f the test lamp remains ON all the time, test for a short to ground on the control circuit. If circuit/connections test normal, replace the
ECM.
瀚慖f the test lamp remains OFF all the time, test for a short to voltage or an open/high resistance on the control circuit. If circuit/connections
test normal, replace the K20 ECM.
5. Test for 2.6-4.6 volts between the control circuit terminal B and ground.
瀚慖f the voltage is not within the specified range, replace the K20 ECM.
6. If all circuits/connections test normal, test or replace the Q13 EVAP vent solenoid valve.
Component Testing
1. Test for 20-24 ohms between the terminals of the Q13 EVAP vent solenoid valve.
瀚慖f not within the specified range, replace the Q13 EVAP vent solenoid valve.
2. Test for infinite resistance between each terminal of the EVAP vent solenoid valve and the EVAP vent solenoid valve housing.
瀚慖f not the specified value, replace the Q13 EVAP vent solenoid valve.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Evaporative Emission Canister Vent Solenoid Valve Replacement (NT7, NU5) (See: Powertrain Management/Emission Control
Systems/Evaporative Emissions System/Evaporative Emission Control Canister/Canister Vent Valve/Service and Repair)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming
P0450
DTC P0450 or P0451 (LAU)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0450
- Fuel Tank Pressure Sensor Circuit
DTC P0451
- Fuel Tank Pressure Sensor Performance
Typical Scan Tool Data
Circuit/System Description
