2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1273

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1273

1. Ignition OFF, disconnect the harness connector at the appropriate B68 knock sensor.

Note: If the voltage is not within the specified range on either circuit, test for a wire to wire short, short to ground, or short to voltage

between the knock sensor circuits.

2. Ignition ON, test for 2-3 V between the signal circuit terminal A or 1 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 or 2 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, 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.

P0333

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