2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1862

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1862

- Secondary Air Injection Pump Control Circuit

DTC P2257

- Secondary Air Injection Pump Relay Control Circuit Low Voltage

DTC P2258

- Secondary Air Injection Pump Relay Control Circuit High Voltage

Diagnostic Fault Information

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. Ignition voltage is supplied directly to the secondary air injection pump relay. The

engine control module (ECM) controls the relay by grounding the control circuit with a solid state device called a driver. The driver is equipped

with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a

voltage by monitoring the feedback voltage.

Conditions for Running the DTC

* The engine speed is greater than 80 RPM.

* The ignition voltage is between 10-18 V.

* The ECM has commanded the air pump relay ON and OFF at least once during the ignition cycle.

* The DTCs run continuously when the above conditions are met.

Conditions for Setting the DTC

P0418

The ECM detects the secondary air injection pump relay control circuit is open.

P2257

The ECM detects the secondary air injection pump relay control circuit is shorted to ground.

P2258

The ECM detects the secondary air injection pump relay control circuit is shorted to voltage.

Action Taken When the DTC Sets

DTC P0418, P2257, and P2258 are Type B DTCs.

Conditions for Clearing the DTC

DTC P0418, P2257, and P2258 are Type B DTCs.

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)