2010 Cadillac CTS Sedan AWD V6-3.6L Page 1053

2010 Cadillac CTS Sedan AWD V6-3.6L Page 1053

circuits/connections test normal, test or replace the appropriate Q17 fuel injector.

Component Testing

Note: The DMM and test leads must be calibrated to 0 ohm in order to prevent misdiagnosis.

1. Remove the intake manifold and disconnect the appropriate Q17 fuel injector.

2. Test for 1.9-2.3 ohm at 20掳C (68掳F) between the high voltage supply circuit terminal 2 and the high voltage control circuit terminal 1 at the

Q17 fuel injector.

瀚慖f not within the specified range, replace the Q17 fuel injector.

3. Measure the resistance between each terminal at the Q17 fuel injector and the Q17 fuel injector housing/case. The DMM should display OL

ohm.

瀚慖f less than the specified value, replace the Q17 fuel injector.

Repair Instructions

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

* Fuel Injector Replacement (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Injector/Service and Repair/Fuel Injector

Replacement)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming

P124D

DTC P1248, P1249, P124A, P124B, P124C, or P124D (w/LF1)

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 P1248

- Cylinder 1 Injector High Control Circuit Shorted to Control Circuit

DTC P1249

- Cylinder 2 Injector High Control Circuit Shorted to Control Circuit

DTC P124A

- Cylinder 3 Injector High Control Circuit Shorted to Control Circuit

DTC P124B

- Cylinder 4 Injector High Control Circuit Shorted to Control Circuit

DTC P124C

- Cylinder 5 Injector High Control Circuit Shorted to Control Circuit

DTC P124D

- Cylinder 6 Injector High Control Circuit Shorted to Control Circuit

Diagnostic Fault Information

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2010 Cadillac CTS Sedan AWD V6-3.6L Page 819

瀚慖f a DTC failed this ignition, test or replace the appropriate Q17 fuel injector.

3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the

conditions that you observed from the Freeze Frame/Failure Records data.

Repair Instructions

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

Fuel Injector Replacement (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Injector/Service and Repair/Fuel Injector

Replacement)

P02B1

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.

Action Taken When the DTC Sets

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2010 Cadillac CTS Sedan AWD V6-3.6L Page 1056

circuits/connections test normal, test or replace the appropriate Q17 fuel injector.

Component Testing

Note: The DMM and test leads must be calibrated to 0 ohm in order to prevent misdiagnosis.

1. Remove the intake manifold and disconnect the appropriate Q17 fuel injector.

2. Test for 1.9-2.3 ohm at 20掳C (68掳F) between the high voltage supply circuit terminal 2 and the high voltage control circuit terminal 1 at the

Q17 fuel injector.

瀚慖f not within the specified range, replace the Q17 fuel injector.

3. Measure the resistance between each terminal at the Q17 fuel injector and the Q17 fuel injector housing/case. The DMM should display OL

ohm.

瀚慖f less than the specified value, replace the Q17 fuel injector.

Repair Instructions

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

* Fuel Injector Replacement (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Injector/Service and Repair/Fuel Injector

Replacement)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming

P0128

DTC P0128 (w/LF1)

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 Descriptor

DTC P0128

- Engine Coolant Temperature (ECT) Below Thermostat Regulating Temperature

Circuit Description

The engine control module (ECM) monitors the temperature of the engine coolant for engine control and as an enabling criteria for some

diagnostics. The amount of air flow into an engine is proportional to the amount of heat an engine generates. The ECM monitors the amount of air

flow into the engine to calculate engine coolant temperature (ECT). The ECM uses the calculated temperature to determine if the engine has

warmed up to the closed loop temperature or to the thermostat regulating temperature. If the coolant temperature does not increase normally or does

not reach the closed loop temperature, diagnostics that use the ECT as enabling criteria, may not run when expected.

Conditions for Running the DTC

P0128

* Before the ECM can report DTC P0128 failed, DTC P0117 and P0118 must run and pass.

* DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0114, P0116, P0117, P0118, P0121, P0122, P0123, P0502, or P0503 is

not set.

* The Engine has not run for greater than 30 minutes.

* The Engine run time from a cold start is greater than 2 minutes.

* The ECT is colder than 50掳C (122掳F) at start up.

* The vehicle speed is greater than 8 km/h (5 mph) for more than 2.4 km/h (1.5 miles).

* The Ethanol content of the fuel is less than 87 percent.

* DTC P0128 runs continuously once the above conditions have been met for approximately 15 min.

OR

* DTCs P0116, P0117, or P0118 is not set.

* The block heater is not detected.

* DTC P0128 runs continuously once the above conditions have been met for approximately 8 min.

Conditions for Setting the DTC

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and the ignition circuit fuse is open, test or replace the appropriate Q17 fuel injector.

3. Test for 2.6-4.6 V between the appropriate fuel injector control circuit listed below and ground.

* Injector 1 terminal 3

* Injector 2 terminal 6

* Injector 3 terminal 4

* Injector 4 terminal 7

* Injector 5 terminal 5

* Injector 6 terminal 8

瀚慖f less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace

the K20 Engine Control Module.

瀚慖f greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control

Module.

4. Probe the appropriate fuel injector control circuit listed below with a test lamp connected to B+. Engine cranking, verify the test lamp flashes.

* Injector 1 terminal 3

* Injector 2 terminal 6

* Injector 3 terminal 4

* Injector 4 terminal 7

* Injector 5 terminal 5

* Injector 6 terminal 8

瀚慖f the test lamp remains OFF, test the control circuit for a high resistance. If the circuit/connections test normal, replace the K20 Engine

Control Module.

Note: Testing for steps 5 and 6 is performed on the fuel injector side of the multi-way harness connector. It may be necessary to remove the

intake manifold to isolate the condition.

5. Ignition OFF, test for infinite resistance between the ignition voltage circuit terminal listed below and ground.

* Injector 1 terminal 3

* Injector 2 terminal 6

* Injector 3 terminal 4

* Injector 4 terminal 7

* Injector 5 terminal 5

* Injector 6 terminal 8

瀚慖f not the specified value, repair the ignition voltage, or control circuit, for a short to ground. If the circuits/connections test normal, test

or replace the appropriate Q17 fuel injector.

6. Test for 12-16 ohm between the appropriate ignition voltage circuit terminal 1 or 2 and each fuel injector control circuit listed below.

* Injector 1 terminal 3

* Injector 2 terminal 6

* Injector 3 terminal 4

* Injector 4 terminal 7

* Injector 5 terminal 5

* Injector 6 terminal 8

瀚慖f less than the specified range, test for a short between the control circuit and the ignition voltage circuit. If the circuits/connections test

normal, test or replace the appropriate Q17 fuel injector.

瀚慖f greater than the specified range, test the ignition voltage, and fuel injector control circuit, for an open/high resistance. If the

circuits/connections test normal, test or replace the appropriate Q17 fuel injector.

Repair Instructions

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

* Fuel Injector Replacement (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Injector/Service and Repair)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for Engine Control Module replacement, setup, and

programming

P0204

DTC P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, or P0277

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and the ignition circuit fuse is open, test or replace the appropriate Q17 fuel injector.

3. Test for 2.6-4.6 V between the appropriate fuel injector control circuit listed below and ground.

* Injector 1 terminal 3

* Injector 2 terminal 6

* Injector 3 terminal 4

* Injector 4 terminal 7

* Injector 5 terminal 5

* Injector 6 terminal 8

瀚慖f less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace

the K20 Engine Control Module.

瀚慖f greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control

Module.

4. Probe the appropriate fuel injector control circuit listed below with a test lamp connected to B+. Engine cranking, verify the test lamp flashes.

* Injector 1 terminal 3

* Injector 2 terminal 6

* Injector 3 terminal 4

* Injector 4 terminal 7

* Injector 5 terminal 5

* Injector 6 terminal 8

瀚慖f the test lamp remains OFF, test the control circuit for a high resistance. If the circuit/connections test normal, replace the K20 Engine

Control Module.

Note: Testing for steps 5 and 6 is performed on the fuel injector side of the multi-way harness connector. It may be necessary to remove the

intake manifold to isolate the condition.

5. Ignition OFF, test for infinite resistance between the ignition voltage circuit terminal listed below and ground.

* Injector 1 terminal 3

* Injector 2 terminal 6

* Injector 3 terminal 4

* Injector 4 terminal 7

* Injector 5 terminal 5

* Injector 6 terminal 8

瀚慖f not the specified value, repair the ignition voltage, or control circuit, for a short to ground. If the circuits/connections test normal, test

or replace the appropriate Q17 fuel injector.

6. Test for 12-16 ohm between the appropriate ignition voltage circuit terminal 1 or 2 and each fuel injector control circuit listed below.

* Injector 1 terminal 3

* Injector 2 terminal 6

* Injector 3 terminal 4

* Injector 4 terminal 7

* Injector 5 terminal 5

* Injector 6 terminal 8

瀚慖f less than the specified range, test for a short between the control circuit and the ignition voltage circuit. If the circuits/connections test

normal, test or replace the appropriate Q17 fuel injector.

瀚慖f greater than the specified range, test the ignition voltage, and fuel injector control circuit, for an open/high resistance. If the

circuits/connections test normal, test or replace the appropriate Q17 fuel injector.

Repair Instructions

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

* Fuel Injector Replacement (See: Powertrain Management/Fuel Delivery and Air Induction/Fuel Injector/Service and Repair)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for Engine Control Module replacement, setup, and

programming

P0267

DTC P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, or P0277