2010 Cadillac Truck SRX FWD V6-3.0L Page 1503
and Repair)
* For DTC P0452 or P0453, always perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic
procedure.
* For DTC P0451 or P0454, clear DTCs with a scan tool.
* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming
P0452
DTC P0451-P0454 (LF1)
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 P0451
- Fuel Tank Pressure Sensor Performance
DTC P0452
- Fuel Tank Pressure Sensor Circuit Low Voltage
DTC P0453
- Fuel Tank Pressure Sensor Circuit High Voltage
DTC P0454
- Fuel Tank Pressure Sensor Intermittent
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The fuel tank pressure sensor measures air pressure or vacuum in the evaporative emission (EVAP) system. The engine control module (ECM)
supplies a 5V reference and a low reference circuit to the fuel tank pressure sensor. The fuel tank pressure sensor signal voltage varies depending
on EVAP system pressure or vacuum. The controller also uses this fuel tank pressure 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 minutes.
