2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1266

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1266

test normal, replace the K20 ECM.

瀚慖f greater than the specified range, test the low reference circuit for a short to voltage. If the circuits/connections test normal, replace the

K20 ECM.

4. If all circuits/connections test normal, test or replace the appropriate B68 knock sensor.

Repair Instructions

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

* Knock Sensor Replacement - Bank 1 (See: Powertrain Management/Computers and Control Systems/Knock Sensor/Service and

Repair/Knock Sensor Replacement - Bank 1)

* Knock Sensor Replacement - Bank 2 (See: Powertrain Management/Computers and Control Systems/Knock Sensor/Service and

Repair/Knock Sensor Replacement - Bank 2)

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

programming.

P0328

DTC P0326, P0327, P0328, P0331, P0332, or P0333 (LAU)

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 P0326

- Knock Sensor System Performance Bank 1

DTC P0327

- Knock Sensor Circuit Low Voltage Bank 1

DTC P0328

- Knock Sensor Circuit High Voltage Bank 1

DTC P0331

- Knock Sensor System Performance Bank 2

DTC P0332

- Knock Sensor Circuit Low Voltage Bank 2

DTC P0333

- Knock Sensor Circuit High Voltage Bank 2

Circuit/System Description

The knock sensor is a piezoelectric device that produces an AC voltage of different amplitude and frequency depending on the level of engine

mechanical vibration. The knock sensor system monitors the knock sensor in order to determine if detonation or spark knock is present. If the

knock sensor system determines that excessive knock is present, the engine control module (ECM) retards the spark timing based on the signal

from the knock sensor system. The knock sensor produces an AC signal when specific frequencies are detected. The ECM then retards the timing

until knock is controlled.

In order to differentiate between normal engine noise and spark knock, the ECM samples the knock sensor signal. The ECM samples the knock

sensor signal for a certain length of time under different engine speeds and loads during non-cylinder knock events. This sampling is used to

determine a range of acceptable normal engine noise.

Conditions for Running the DTC

P0326 and P0331

* The engine speed is greater than 1,600 RPM.

* The ECM is controlling spark.

* DTCs P0326 and P0331 run continuously once the above conditions are met.