2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1271
Repair/Knock Sensor Replacement - Bank 2)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for Engine Control Module replacement, setup, and
programming.
P0332
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.
P0327, P0328, P0332, and P0333
* DTCs P0324, P0335, P0336, P0338, P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, P0393 are not set.
* The engine speed is greater than 1,960 RPM.
* The ECM is controlling spark.
* The increase in engine speed is less than a range of 1,400-3,700 RPM per second.
* The engine load is in the range of 35-65 kPa per second.
* DTCs P0327, P0328, P0332, and P0332 run continuously once the above conditions are met for approximately 20 s.
Conditions for Setting the DTC
P0326 and P0331
The ECM detects a knock sensor signal voltage that is not in the range of a predetermined engine noise level in 25 of 250 test samples. The
