2010 Cadillac Truck SRX FWD V6-3.0L Page 1503

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.