2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1367

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1367

K20 ECM.

6. If all circuits test normal, test or replace the B150 fuel tank pressure 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)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming

P0455

DTC P0455 or P0497 (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 Descriptor

DTC P0455

- Evaporative Emission (EVAP) System Large Leak Detected

DTC P0497

- Evaporative Emission (EVAP) System No Flow During Purge

Circuit/System Description

The ECM tests the Evaporative Emission (EVAP) System for a large leak or restrictions to the purge path in the EVAP system. When the enabling

criteria has been met the ECM commands the evaporative emission canister vent solenoid valve ON and the evaporative emission canister purge

solenoid valve ON, allowing vacuum into the evaporative emission system. The ECM monitors the fuel tank pressure sensor voltage to verify that

the system is able to reach a predetermined level of vacuum within a set amount of time.

The following table illustrates the relationship between the ON and OFF states, and the OPEN or CLOSED states of the EVAP canister purge and

vent valves.

Conditions for Running the DTC

* Before the engine control module (ECM) can report DTC P0455 or DTC P0497 failed, DTCs P0446 and P0496 must run and pass.

* DTC P0100, P0101, P0102, P0103, P0111, P0112, P0113, P0116, P0117, P0118, P0119, P0443, P0446, P0449, P0450, P0451, P0452,

P0453, P0458, P0459, P0496, P0498, P0499, P0502, P0503, P0560, P0562, P0563, P0700, P2122, P2123, P2127, P2128, P2138, P2227,

P2228, or P2229 is not set.

* The ignition voltage is between 10-18 V.

* The engine run time is greater than 10 min or the fuel trim is stable.

* The fuel tank pressure is between -18.7 and +9.8 mm Hg (-10.0 and +5.2 in. H2O).

* The Closed Loop fuel control is enabled.

* The engine is idling.

* The barometric pressure (BARO) is greater than 68 kPa.

* The fuel level is between 11-88 %.

* The ambient air temperature (IAT) is between 2-32掳C (36-90掳F).

* The engine coolant temperature (ECT) is within 10掳C (18掳F) of the ambient air temperature at engine start.

* The vehicle speed sensor (VSS) is less than 3 km/h (2 mph).