2010 Cadillac CTS Sedan AWD V6-3.6L Page 818
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
Fuel System Description (See: Powertrain Management/Computers and Control Systems/Description and Operation/Fuel System Description)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
Circuit/System Verification
1. Clear the DTC information with a scan tool.
2. Engine operating, raise the engine speed to 2,000 RPM. Observe the DTC information with a scan tool. DTC P029D, P02A1, P02A5,
P02A9, P02AD, or P02B1 should not set.
