2010 Cadillac Truck SRX FWD V6-3.0L Page 1483

2010 Cadillac Truck SRX FWD V6-3.0L Page 1483

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 P0411

- Secondary Air Injection System Incorrect Air Flow Detected

Circuit/System Description

The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the

exhaust stream in order to accelerate the catalyst operation. An secondary air injection system pressure sensor is used to monitor the air flow from

the secondary air injection pump. The ECM supplies voltage to the 5 V reference circuit and a ground to the low reference circuit. The sensor

provides a signal voltage to the ECM relative to the pressure changes within the secondary air injection system.

Ignition voltage is supplied directly to the secondary air injection pump relay. The ECM controls the relay by grounding the control circuit, which

activates the secondary air injection pump relay. With the relay contacts closed, battery voltage is supplied to the secondary air injection pump.

Conditions for Running the DTC

* DTC P0100, P0101, P0102, P0103, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0119, P0418, P050C, P2227, P2228, P2229,

P2257, or P2258 is not set.

* Greater than 60 min has elapsed since the last cold start.

* The secondary air injection system has been commanded ON and OFF during the ignition cycle.

* The battery voltage is between 10-18 V.

* The engine speed is between 680-3,500 RPM.

* The Intake Air Temperature (IAT) is between -12 to +80掳C (10.4-176掳F).

* The Engine Coolant Temperature (ECT) is between -10.5 to +69.8掳C (13-158掳F).

* The Mass Air Flow (MAF) is less than 100 g/s.

* Catalyst heating is active.

* The Barometric Pressure (BARO) is less than 68 kPa (9.9 psi).

* The difference between intake air temp and engine coolant start temp is less than 15掳C (27掳F).

* DTC P0411 runs once per ignition cycle when the above conditions are met.

Conditions for Setting the DTC

* The ratio of the calculated secondary air mass flow to the modeled secondary air mass flow is less than 0.75 or greater than 1.2.

* DTC P0411 sets within 60 s when the above condition is met.

Action Taken When the DTC Sets

DTC P0411 is a Type B DTC.

Conditions for Clearing the DTC

DTC P0411 is a Type B DTC.

Reference Information

Schematic Reference

Engine Controls Schematics (LAU) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)Engine Controls Schematics

(LF1) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views/Connector End Views By Name)

Description and Operation

Secondary Air Injection System Description (See: Powertrain Management/Emission Control Systems/Air Injection/Description and Operation)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit

Testing/Circuit Testing)

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic