AutoCodes – Generic – P2338

P2338 Code - Cylinder 3 Above Knock Threshold

Quick Answer

The Knock Sensor (KS) senses engine knocking (also known as detonation or pinging) using a piezoelectric element. Common causes include Faulty knock sensor, Knock sensor circuit poor electrical connection, Knock sensor 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: P2338 indicates Cylinder 3 Above Knock Threshold.
Common causes: Common causes include Faulty knock sensor, Knock sensor circuit poor electrical connection, Knock sensor 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 15,941

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P2338 Description

The Knock Sensor (KS) senses engine knocking (also known as detonation or pinging) using a piezoelectric element. The sensor is attached to the cylinder block, cylinder head or intake manifold. A knocking vibration from the cylinder block is sensed as vibrational pressure. This pressure is converted into a voltage signal and sent to the Engine Control Module (ECM). The ECM uses this signal to retard the ignition timing and protect the engine from this damaging pre-ignition.

OBDII Code P2338 - Cylinder 3 Above Knock Threshold - AutoCodes.com — P2338 Code - Cylinder 3 Above Knock Threshold

What does this mean?

What are the Possible Causes of the DTC P2338?

Faulty knock sensor
Knock sensor circuit poor electrical connection
Knock sensor harness is open or shorted
Faulty Engine Control Module (ECM)

How to Fix the DTC P2338?

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 P2338 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 P2338 code?

Need more information on how to fix the P2338 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P2338 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P2338 Dodge — Cylinder 3 Above Knock Threshold
P2338 Ford — Cylinder 3 Above Knock Threshold
P2338 Lincoln — Cylinder 3 Above Knock Threshold
P2338 Mercury — Cylinder 3 Above Knock Threshold

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 P2338 Code

1. What are the common symptoms of OBDII code P2338 (Cylinder 3 Above Knock Threshold)?

- Common symptoms include engine knocking or pinging noises, reduced engine performance, and in some cases, the Check Engine light may illuminate.

2. What are the possible causes of OBDII code P2338?

- The code P2338 can be triggered by issues such as a faulty knock sensor, a problem with the cylinder 3 ignition system, engine misfire, or a mechanical problem within the cylinder.

3. How does a faulty knock sensor contribute to OBDII code P2338?

- A malfunctioning knock sensor can inaccurately detect engine knocking, leading to the ECM setting the code P2338 for cylinder 3 when no actual knocking is present.

4. What are some tips for repairing OBDII code P2338?

- Some common repair tips include checking and replacing the knock sensor, inspecting the ignition system components related to cylinder 3, diagnosing and addressing any engine misfires, and ensuring proper engine mechanical function.

5. Can driving with OBDII code P2338 cause further damage to the vehicle?

- Continuing to drive with code P2338 can potentially lead to engine damage if the underlying issue, such as engine knocking, is not addressed promptly. It is recommended to address the problem as soon as possible.

6. How can a mechanic diagnose OBDII code P2338?

- Mechanics can diagnose code P2338 by using a scan tool to retrieve the code and then conducting a series of tests to pinpoint the exact cause, such as conducting a visual inspection, testing the knock sensor, checking the ignition system, and performing a cylinder balance test.

7. Are there any DIY steps to troubleshoot OBDII code P2338 before taking the vehicle to a mechanic?

- DIY steps for troubleshooting code P2338 include checking the knock sensor wiring for any damage, visually inspecting the ignition components for issues, and ensuring proper cylinder 3 spark plug operation.

8. How important is it to address OBDII code P2338 promptly?

- It is crucial to address code P2338 promptly to prevent potential engine damage and ensure the vehicle's optimal performance and fuel efficiency.

9. Can OBDII code P2338 be intermittent or sporadic?

- Yes, code P2338 can sometimes be intermittent or sporadic, especially if the issue is related to a loose connection or occasional engine knocking that triggers the code.

10. Is it safe to drive the vehicle with the Check Engine light on due to code P2338?

- While it may be safe to drive the vehicle for a short distance with the Check Engine light on, it is advisable to have the issue diagnosed and repaired as soon as possible to prevent any potential damage or performance issues.