2010 Cadillac CTS Sedan AWD V6-3.6L Page 1316
sensor circuits.
2. Ignition ON, test for 2-3 V between the signal circuit terminal A and ground.
瀚慖f less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuits/connections test
normal, replace the K20 ECM.
瀚慖f greater than the specified range, test the signal circuit for a short to voltage. If the circuits/connections test normal, replace the K20
ECM.
3. Test for 2-3 V between the low reference circuit terminal B and ground.
瀚慖f less than the specified range, test the low reference circuit for a short to ground or an open/high resistance. If the circuits/connections
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, replace the B68 knock sensor 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 ECM replacement, setup, and programming
P0327
DTC P0326, P0327, P0328, P0331, P0332, or P0333 (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 P0326
- Knock Sensor 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 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
