2010 Cadillac Truck SRX FWD V6-3.0L Page 1883

2010 Cadillac Truck SRX FWD V6-3.0L Page 1883

* 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) provide an overview of each diagnostic category.

DTC Descriptor

DTC P1400

- Cold Start Emission Reduction Control System

Circuit/System Description

The catalytic converter must be warmed to efficiently reduce the emissions. The cold start strategy is to reduce the amount of time it takes to warm

the catalytic converter. During a cold start, the engine idle speed is elevated and spark timing is retarded to allow the catalyst to warm quickly. This

diagnostic monitors the following to build an exhaust energy model:

* Engine speed

* Spark advance

* Throttle position

* Engine coolant temperature

* Engine run time

* Park/neutral position

* Vehicle speed

The actual model is then compared to the expected exhaust energy model.

Conditions for Running the DTC

* The engine is running, and a cold start has been detected.

* Vehicle speed is less than 3 km/h (2 mph).

* The engine is at idle with no input from the accelerator pedal.

* The calculated catalyst temperature is less than 100掳C (212掳F).

* Engine coolant is greater than 10掳C (50掳F) and less than 56掳C (132掳F).

* DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220,

P0222, P0223, P0201, P0202, P0203, P0204, P0205, P0206, P0300, P0335, P0336, P0351, P0352, P0353, P0501, P0502, P0506, P0507,

P0601, P0602, P0603, P0604, P0606, P0607, P060D, P062F, P0641, P0651, P1101, P1516, P1682, P2101, P2119, P2120, P2122, P2123,

P2125, P2127, P2128, P2135, P2138, P2176, P2610 are not set.

This DTC runs for 12 s within the first 17 s of start-up, or until the calculated catalyst temperature is greater than 900掳C (1,652掳F). This diagnostic

runs once per trip when a cold start has been determined.

Conditions for Setting the DTC

The actual exhaust energy model does not match the expected exhaust energy model.

Action Taken When the DTC Sets

DTC P1400 is a Type A DTC.

Conditions for Clearing the MIL/DTC

DTC P1400 is a Type A DTC.

Reference Information

Description and Operation

Engine Control Module Description (See: Powertrain Management/Computers and Control Systems/Description and Operation/Engine Control

Module Description)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code

(DTC) Type Definitions)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information