2010 Cadillac Truck Escalade AWD V8-6.2L Page 2130

DTC P0328

- Knock Sensor (KS) Circuit High Voltage Bank 1

DTC P0330

- Knock Sensor (KS) Circuit Bank 2

DTC P0332

- Knock Sensor (KS) Circuit Low Voltage Bank 2

DTC P0333

- Knock Sensor (KS) Circuit High Voltage Bank 2

Diagnostic Fault Information

Circuit/System Description

The knock sensor (KS) system enables the engine control module (ECM) to control the ignition timing for the best possible performance while

protecting the engine from potentially damaging levels of detonation. The ECM monitors 2 separate KS, one on each side of the engine block. Each

KS produces an AC voltage that varies, depending on the vibration levels detected during engine operation. The ECM receives the KS signal

through 2 isolated signal circuits for each KS. The ECM adjusts the spark timing based on the amplitude and frequency of each KS signal. The

ECM learns a minimum noise level for each sensor at idle speeds, and uses calibrated noise level values for the rest of the RPM range. The ECM

should monitor a normal KS signal within the noise channel.

Conditions for Running the DTC

P0324

* DTC P0325, P0326, P0327, P0328, P0330, P0332, or P0333 are not set.

* The engine speed is at least 400 RPM.

* DTC P0324 runs continuously when the above conditions are met.

P0325 or P0330

* DTC P0324, P0325, P0326, P0327, P0328, P0330, P0332, or P0333 are not set.

* The engine speed is at least 400 RPM.

* The engine coolant temperature (ECT) is warmer than -40锟斤拷C (-40锟斤拷F).

* The engine run time is at least 2 s.

* The power take-off (PTO) is not active.

* DTCs P0325 and P0330 run continuously when the above conditions are met.

P0326

* DTC P0068, P0606, P1516, P2101, P2135, or P2176 are not set.

* The engine speed is at least 400 RPM.

* The MAP is at least 10 kPa.

* DTC P0324 runs continuously when the above conditions are met.

P0327, P0328, P0332, and P0333

* The engine coolant temperature (ECT) is warmer than -40锟斤拷C (-40锟斤拷F).

* The engine run time is at least 2 s.

* DTCs P0327, P0328, P0332, and P0333 run continuously when the above conditions are met.

Conditions for Setting the DTC

P0324

The ECM has detected an internal circuitry fault for 5 s.

P0325 and P0330

The KS signal circuits are open or shorted together for 5 s.

P0326

* The KS signal indicates an engine knock is present.

* The ECM has commanded the spark retard to a value, which is more than the calibrated value, for a specific engine load and speed.

* The above conditions exist for more than 5 s.

2010 Cadillac CTS Sedan AWD V6-3.6L Page 1319

2010 Cadillac CTS Sedan AWD V6-3.6L Page 1319

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

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

* DTC P0324 is not set.

* The engine coolant temperature (ECT) sensor is warmer than 60掳C (140掳F).

* The engine speed is greater than 2,200 RPM.

* The increase in engine speed is less than 500-2,300 RPM per second.

* The increase in engine load is less than a range of 50-100 kPa per second.

* DTCs P0326 and P0331 run continuously once the above conditions are met for approximately 20 s.

P0327, P0328, P0332, and P0333

* DTC P0324 is not set.

* The engine coolant temperature (ECT) sensor is warmer than 60掳C (140掳F).

* The increase in engine speed is less than a range of 500-2300 RPM per second.

* The increase in engine load is less than a range of 50-100 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 short to ground or a voltage on the knock sensor signal circuits in 25 of 250 test samples. The condition exists for greater than 1

s or for a cumulative of 10 s.

P0327 or P0332

The ECM detects the knock sensor signal voltage is less than the calculated minimum for a predetermined engine noise level. The condition exists

during 2 consecutive tests, for greater 1 s or a cumulative of 10 s.

P0328 or P0333

The ECM detects the knock sensor signal voltage is greater than the calculated maximum for a predetermined engine noise level. The condition

exists during 2 consecutive tests, for greater 1 s or a cumulative of 10 s.

Action Taken When the DTC Sets

DTCs P0326, P0327, P0328, P0331, P0332, and P0333 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0326, P0327, P0328, P0331, P0332, and P0333 are Type B DTCs.

Diagnostic Aids

* Inspect the knock sensor for physical damage. A knock sensor that is dropped or damaged may cause a DTC to set.