AutoCodes – Chevrolet – P1338 2018 Chevrolet Silverado

P1338 2018 Chevrolet Silverado Code - Cylinder 1 Glow Plug Offset Exceeded Learning Limit

Quick Answer

The Glow Plug Control Module has not learned the glow plug offset values. Common causes include Perform Glow Plug Learn procedure, Faulty Glow Plug 1, Glow Plug 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: P1338 2018 Chevrolet Silverado indicates Cylinder 1 Glow Plug Offset Exceeded Learning Limit.
Common causes: Common causes include Perform Glow Plug Learn procedure, Faulty Glow Plug 1, Glow Plug 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 558

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Sep 30, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P1338 2018 Chevrolet Silverado Description

The Glow Plug Control Module has not learned the glow plug offset values. If a glow plug has been replaced and the glow plug learn was not performed, or if the Glow Plug Control Module experiences an Electronically Erasable Programmable Read Only Memory (EEPROM) error or data corruption, this Diagnostic Trouble Code (DTC) to set. The DTC will be set if the glow plug hot resistance is outside a predefined threshold.

OBDII Code P1338 2018 Chevrolet Silverado - Cylinder 1 Glow Plug Offset Exceeded Learning Limit - AutoCodes.com — P1338 2018 Chevrolet Silverado Code - Cylinder 1 Glow Plug Offset Exceeded Learning Limit

What does this mean?

What are the Possible Causes of the DTC P1338 2018 Chevrolet Silverado?

Perform Glow Plug Learn procedure
Faulty Glow Plug 1
Glow Plug 1 harness is open or shorted
Glow Plug 1 circuit poor electrical connection

How to Fix the DTC P1338 2018 Chevrolet Silverado?

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 does this mean?

Code Tech Notes

If a Glow Plug was replaced, perform a Glow Plug Learn procedure with a Scan Tool.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1338 2018 Chevrolet Silverado 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 P1338 2018 Chevrolet Silverado code?

Need more information on how to fix the P1338 2018 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1338 2018 Chevrolet Silverado code diagnosed by a professional: Find a repair shop in your area

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 P1338 2018 Chevrolet Silverado Code

What does OBDII code P1338 mean on a 2018 Chevrolet Silverado?

P1338 indicates that the glow plug offset learning limit for cylinder 1 has been exceeded, which means the system has detected an issue with the glow plug or its performance.

What are the symptoms of code P1338 on a 2018 Chevrolet Silverado?

Common symptoms include difficulty starting the engine in cold weather, rough idling, reduced fuel efficiency, and an illuminated check engine light.

What causes the P1338 code to appear on a 2018 Chevrolet Silverado?

Causes may include a faulty glow plug in cylinder 1, an issue with the glow plug control module, wiring problems, or carbon buildup affecting the glow plugâ€™s performance.

Can I drive my 2018 Chevrolet Silverado with the P1338 code?

While the truck may still be drivable, ignoring the issue can lead to harder starts, reduced performance, and potential long-term engine damage, especially in cold climates.

How do I diagnose the P1338 code on a 2018 Chevrolet Silverado?

Diagnosis involves scanning for codes, inspecting the glow plug in cylinder 1, testing the glow plug for proper resistance, and checking the wiring and connections to the glow plug control module.

How do I fix the P1338 code on a 2018 Chevrolet Silverado?

Repairs may include replacing the faulty glow plug, cleaning or replacing carbon-damaged components, repairing wiring issues, or replacing the glow plug control module if necessary.

What tools are needed to fix the P1338 code on a 2018 Chevrolet Silverado?

Youâ€™ll need an OBDII scanner, a multimeter to test resistance, and basic hand tools to replace the glow plug or repair wiring.

How much does it cost to fix the P1338 code on a 2018 Chevrolet Silverado?

The cost can vary, but replacing a glow plug typically costs between $50 and $200, including parts and labor. Additional wiring or module repairs may increase the cost.

Can cold weather cause the P1338 code on a 2018 Chevrolet Silverado?

Extreme cold can exacerbate glow plug issues, making it harder for the engine to start and potentially triggering the P1338 code.

Do glow plugs require regular maintenance to avoid the P1338 code?

Glow plugs generally donâ€™t require regular maintenance, but they should be inspected and replaced as part of routine diesel engine care, especially if starting issues arise.