2010 Cadillac CTS Sedan AWD V6-3.6L Page 1425
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 P0451
- Fuel Tank Pressure (FTP) Sensor Performance
DTC P0452
- Fuel Tank Pressure (FTP) Sensor Circuit Low Voltage
DTC P0453
- Fuel Tank Pressure (FTP) Sensor Circuit High Voltage
DTC P0454
- Fuel Tank Pressure (FTP) Sensor Intermittent
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The fuel tank pressure (FTP) sensor measures air pressure or vacuum in the evaporative emission (EVAP) system. The engine control module
(ECM) supplies a 5 V reference and a low reference circuit to the FTP sensor. The FTP sensor signal voltage varies depending on EVAP system
pressure or vacuum. The controller also uses this FTP signal to determine atmospheric pressure for use in the engine-off small leak test, DTC
P0442. Before using this signal as an atmospheric reference it must first be re-zeroed.
Conditions for Running the DTC
P0451
* DTC P0451 runs only when the engine-off natural vacuum small leak test, P0442, executes.
* The number of times this test runs can range from 0-2 per engine-off period. The length of the test can be up to 10 min.
P0452 and P0453
DTC P0452 and P0453 run continuously when the ignition is ON.
P0454
* DTC P0454 runs only when the engine-off natural vacuum small leak test, P0442, executes.
* This test can run once per engine-off period. The length of the test can be up to 10 min.
* A refueling event is not detected.
Conditions for Setting the DTC
P0451
This DTC will set if the controller is unable to re-zero the FTP sensor voltage within a calibrated range during the engine-off small leak test, P0442.
