2010 Cadillac CTS Sedan AWD V6-3.6L Page 816

2010 Cadillac CTS Sedan AWD V6-3.6L Page 816

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 P029D

- Cylinder 1 Injector Leak Detected

DTC P02A1

- Cylinder 2 Injector Leak Detected

DTC P02A5

- Cylinder 3 Injector Leak Detected

DTC P02A9

- Cylinder 4 Injector Leak Detected

DTC P02AD

- Cylinder 5 Injector Leak Detected

DTC P02B1

- Cylinder 6 Injector Leak Detected

Circuit/System Description

The fuel injectors are mounted in the cylinder head beneath the intake ports and spray fuel directly into the combustion chamber. Direct injection

requires high fuel pressure due to the fuel injector's location in the combustion chamber. High pressure fuel is regulated by the high pressure fuel

pump actuator, which is a part of the high pressure fuel pump. The engine control module (ECM) monitors the actual fuel rail fuel pressure via the

fuel rail pressure sensor and commands the high pressure fuel pump actuator duty cycle in order to maintain the desired fuel rail pressure. If a fuel

injector delivers more fuel than is needed misfire counts will accumulate on that cylinder, and the ECM will not be able to maintain the desired fuel

rail pressure, indicating a stuck open or leaking fuel injector.

Conditions for Running the DTC

* The engine speed is between 1,520-6,000 RPM

* The engine load is less than 190 percent.

* The misfire monitor is enabled.

* DTCs P029D, P02A1, P02A5, P02A9, P02AD, and P02B1 run continuously once the conditions above have been met for approximately 20

seconds.

Conditions for Setting the DTC

The ECM detects a specific cylinder misfire rate of greater than 30 counts in less than 17 engine revolutions, and P0087 is set. The condition exists

for greater than 4 seconds or for a cumulative of 30 seconds.

Action Taken When the DTC Sets

* DTCs P029D, P02A1, P02A5, P02A9, P02AD, and P02B1 are Type A DTCs.

* The control module commands the engine to operate in the Reduced Engine Power mode.

* The message center displays Reduced Engine Power.

Conditions for Clearing the DTC

DTCs P029D, P02A1, P02A5, P02A9, P02AD, and P02B1 are Type A DTCs.

Diagnostic Aids

A fuel injector leak into the combustion chamber may result in mechanical damage to the cylinder.

Reference Information

Schematic Reference

Engine Controls Schematics (LLT) (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)

Description and Operation