Purpose

This article outlines the procedures to diagnose and confirm Diagnostic Trouble Code (DTC) P0332 on a 2018 Chevrolet Tahoe V6, 5.3L and replace the Knock Sensor to resolve the issue.

Introduction

In cases where the Malfunction Indicator Lamp (MIL) on your vehicle’s dashboard is illuminated, and the Engine Control Module (ECM) has stored DTC P0332, it indicates the ECM has detected that the Knock Sensor is not operating properly. A faulty Knock Sensor can cause engine performance problems.

The Knock Sensor is an auxiliary sensor that is part of the electronic spark control circuit. The Knock Sensor detects engine vibrations caused by "knocking" (cylinder detonation) and converts the vibrations into an AC signal that is sent to the ECM. The ECM then momentarily retards spark timing to eliminate the knock condition. Once the knocking stops, spark timing returns to normal.

Symptoms of DTC P0332 include:

• Malfunction Indicator Lamp (MIL) ON or flashing
• Reduced engine power and performance
• Fluctuation of engine speed
• Hesitation

Possible causes of this fault are:

• Faulty Knock Sensor
• Fault in the Knock Sensor circuit

When DTC P0332 is present on a 2018 Chevrolet Tahoe V6, 5.3L, replacing the Knock Sensor may resolve the issue.

	Step Time required (hour) Sections Cautions Level	3 2.0 3 0 ***

Model	Part number	Part name
Chevrolet Tahoe	12623095	Knock Sensor

(This image is for illustrative purposes only and may not match the actual part number)

Diagnostic Procedures:

Initial Inspection

During your initial inspection, check for obvious signs such as blown or missing fuses, broken or damaged connectors, open wires, and harnesses. In addition, inspect the battery terminals and check the state of charge before attempting to diagnose possible electrical faults. This fault may be caused by a disconnected Knock Sensor (KS). Refer to the Vehicle Emissions Warranty Manual for time and mileage coverage for the emissions-related fault(s). For additional information, refer to the Service Manual or applicable Technical Service Bulletin (TSB).

Diagnostic Procedures

a. Disconnect the KS connector. Turn the ignition to the Key ON Engine OFF (KOEO) position. Using a Digital Multimeter (DMM), measure the voltage between Pin 1 (White-Grey) and Pin 2 (Black-Grey).  The voltage should be 5V. 

- If the voltage is within specification, replace the KS. Perform Repair Validation. 

- If the voltage is not within specification, check the wire from the KS sensor to Power Control Module (PCM) for open or short circuits. Proceed to Step 1b. 

b. Using a DMM, check the sensor’s resistance. The value should be infinite. 

- If the value is within specification, perform Repair Validation. 

- If the value is not witin specification, replace the KS. Perform Repair Validation.

Replace Knock Sensor

Removal

Step 1 – Remove the starter.

Step 2 – Disconnect the harness connector from the sensor.

Step 3 – Remove the Knock Sensor.

Installation

Installation is accomplished in the reverse order of removal. Tighten the sensor with 25 N.m (18 lb-ft).

Repair Validation:

1. Clear Diagnostic Trouble Codes (DTCs) and Freeze Frame (FF) data.

2. Perform the Key ON Engine OFF (KOEO) and Key ON Engine RUNNING (KOER) test or perform the drive cycle requirements for the fault area.

3. Optionally, operate the vehicle within the conditions recorded in the Freeze Frame data when DTC P0332 was initially set.

4. Check for pending or stored DTCs. If none are found, the repair is complete.