2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1268

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1268

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

1. Engine at operating temperature, all accessories OFF. Engine speed greater than 2,000 RPM, observe the appropriate scan tool knock sensor

signal voltage parameter. The voltage should be greater than 4.0 V.

2. Engine idling, move the related harnesses and connectors for the knock sensor circuits while observing the scan tool knock sensor signal

voltage parameters. The voltage should remain steady with no abrupt changes.

3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the

conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

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.

P0331

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