2010 Cadillac CTS Sedan AWD V6-3.6L Page 909

2010 Cadillac CTS Sedan AWD V6-3.6L Page 909

commanded states.

瀚慖f the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

瀚慖f the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace

the K20 ECM.

4. If all circuits test normal, replace the K27 fuel pump control module.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

Control Module References (See: Testing and Inspection/Programming and Relearning)for ECM or fuel pump control module replacement, setup,

and programming

P029D

DTC P029D, P02A1, P02A5, P02A9, P02AD, or P02B1 (w/LLT)

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 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.