AutoCodes – Buick – P1338 Buick

P1338 Buick 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 Buick 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 545

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 Buick 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 Buick - Cylinder 1 Glow Plug Offset Exceeded Learning Limit - AutoCodes.com — P1338 Buick Code - Cylinder 1 Glow Plug Offset Exceeded Learning Limit

What does this mean?

What are the Possible Causes of the DTC P1338 Buick?

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 Buick?

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 Buick 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 Buick code?

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

Need Help with the Code?

Get the P1338 Buick 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 Buick Code

What does the OBDII code P1338 mean for my Buick?

The P1338 code indicates that the Engine Control Module (ECM) has detected that the learned offset for the glow plug on cylinder 1 has exceeded its acceptable limits, which may affect engine performance and emissions.

What are the common symptoms of the P1338 code?

Common symptoms include poor engine starting, rough idling, increased exhaust emissions, and a noticeable decrease in engine performance.

What could cause the P1338 code to trigger?

Causes can include a faulty glow plug, issues with the glow plug control module, wiring problems, or an incorrect offset value stored in the ECM.

How can I diagnose the issue related to the P1338 code?

Diagnosis can include visually inspecting the glow plugs and wiring, checking for other related trouble codes, and using a scan tool to monitor the glow plug system's performance during operation.

Is it safe to drive my Buick with the P1338 code?

While it may be safe for short trips, driving with this code can lead to rough engine performance and increased emissions, so it's recommended to have the issue diagnosed and repaired as soon as possible.

What repairs are typically needed for a P1338 code?

Repairs may involve replacing the faulty glow plug, repairing wiring or connectors, reprogramming the ECM, or replacing the glow plug control module if itâ€™s determined to be faulty.

Will clearing the P1338 code fix the problem?

Clearing the code may temporarily turn off the check engine light, but it won't fix the underlying issue. The code will likely return if the root cause is not addressed.

How much might it cost to repair the P1338 code?

Repair costs can vary widely based on the underlying issue, but replacing a glow plug may range from $100 to $300, while more extensive repairs could be higher.

Can I reset the ECM to fix the P1338 code?

Resetting the ECM may clear the code temporarily, but it will not resolve the underlying problem. Proper diagnosis and repair are necessary for a permanent fix.