AutoCodes – GMC – P0326 GMC

P0326 GMC Code - Knock Sensor Performance Bank 1

Quick Answer

The Knock Sensor 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, also known as spark knock. Common causes include Faulty Knock Sensor Bank 1, Knock Sensor Bank 1 circuit poor electrical connection, Knock Sensor Bank 1 harness is open or shorted. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0326 GMC indicates Knock Sensor Performance Bank 1.
Common causes: Common causes include Faulty Knock Sensor Bank 1, Knock Sensor Bank 1 circuit poor electrical connection, Knock Sensor Bank 1 harness is open or shorted.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 1,576

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Jun 13, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0326 GMC Description

The Knock Sensor 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, also known as spark knock. The knock sensor system uses one or two flat response 2-wire sensors. The sensor uses piezo-electric crystal technology that produces an AC voltage signal of varying amplitude and frequency based on the engine vibration or noise level. The amplitude and frequency are dependent upon the level of knock that the knock sensor detects. The ECM receives the knock sensor signal through two isolated signal circuits for each knock sensor.
The control module learns a minimum noise level, or background noise, at idle from the knock sensor and uses calibrated values for the rest of the RPM range. The control module uses the minimum noise level to calculate a noise channel. A normal knock sensor signal will ride within the noise channel. As engine speed and load change, the noise channel upper and lower parameters will change to accommodate the normal knock sensor signal, keeping the signal within the channel. In order to determine which cylinders are knocking, the control module only uses knock sensor signal information when each cylinder is near the Top Dead Center (TDC) of the firing stroke. If a knock is present, the signal will range outside of the noise channel.
If the control module has determined that a knock is present, it will retard the ignition timing to attempt to eliminate the knock. The control module will always try to work back to a zero-compensation level, or no spark retard. An abnormal knock sensor signal will stay outside of the noise channel or will not be present. knock sensor diagnostics are calibrated to detect faults with the knock sensor circuitry inside the control module, the knock sensor wiring, or the knock sensor voltage output. Some diagnostics are also calibrated to detect constant noise from an outside influence such as a loose/damaged component or excessive engine mechanical noise.
The Diagnostic Trouble Code (DTC) will be set when the signal from Knock Sensor is low frequency.

OBDII Code P0326 GMC - Knock Sensor Performance Bank 1 - AutoCodes.com — P0326 GMC Code - Knock Sensor Performance Bank 1

What does this mean?

What are the Possible Causes of the DTC P0326 GMC?

Faulty Knock Sensor Bank 1
Knock Sensor Bank 1 circuit poor electrical connection
Knock Sensor Bank 1 harness is open or shorted
Faulty Engine Control Module (ECM)

How to Fix the DTC P0326 GMC?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0326 GMC code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0326 GMC code?

Need more information on how to fix the P0326 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0326 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P0326 2014 GMC Sierra — Knock Sensor Performance Bank 1
P0326 2015 GMC Sierra — Knock Sensor Performance Bank 1
P0326 2016 GMC Sierra — Knock Sensor Performance Bank 1
P0326 2017 GMC Sierra — Knock Sensor Performance Bank 1
P0326 2018 GMC Sierra — Knock Sensor Performance Bank 1

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0326 GMC Code

1. What are the common symptoms of OBDII code P0326 GMC (Knock Sensor Performance Bank 1)?

- Common symptoms include reduced engine performance, engine knocking or pinging noises, and illuminated check engine light.

2. What are the possible causes of OBDII code P0326 GMC?

- The code P0326 GMC is typically triggered by issues such as a faulty knock sensor, wiring or connector problems, engine mechanical issues, or a faulty powertrain control module (PCM).

3. How can I diagnose OBDII code P0326 GMC?

- To diagnose this code, a technician may use a scan tool to read the code and perform further testing on the knock sensor, wiring, connectors, and related components to pinpoint the exact cause.

4. Can I drive my vehicle with OBDII code P0326 GMC?

- It is generally not recommended to drive your vehicle with this code active, as it can lead to engine damage or performance issues. It's best to address the underlying problem as soon as possible.

5. What is the typical repair for OBDII code P0326 GMC?

- The typical repair for this code involves replacing the faulty knock sensor, repairing any wiring or connector issues, addressing any engine mechanical problems, or reprogramming the PCM as necessary.

6. Are there any DIY tips for addressing OBDII code P0326 GMC?

- While some basic troubleshooting like checking for loose connections or damaged wiring can be done by DIYers, it's recommended to have a professional diagnose and repair the issue to ensure proper resolution.

7. How much does it cost to fix OBDII code P0326 GMC?

- The cost of fixing this code can vary depending on the underlying issue, parts needed for replacement, and labor rates. It's best to consult with a mechanic for an accurate estimate.

8. Can a bad knock sensor cause OBDII code P0326 GMC?

- Yes, a faulty knock sensor can trigger the P0326 code as it fails to accurately detect engine knock or pinging, leading to performance issues and potential damage.

9. Will resetting the check engine light resolve OBDII code P0326 GMC?

- Resetting the check engine light may temporarily turn it off, but if the underlying issue causing the P0326 code is not fixed, the light will likely come back on once the problem is detected again.

10. Is OBDII code P0326 GMC a serious issue?

- While driving with this code may not immediately cause your vehicle to break down, it is still important to address it promptly to prevent potential engine damage and ensure optimal performance.