AutoCodes – GMC – P133A 2018 GMC Sierra

P133A 2018 GMC Sierra Code - Cylinder 3 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 3, Glow Plug 3 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: P133A 2018 GMC Sierra indicates Cylinder 3 Glow Plug Offset Exceeded Learning Limit.
Common causes: Common causes include Perform Glow Plug Learn procedure, Faulty Glow Plug 3, Glow Plug 3 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 220

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 Sep 30, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P133A 2018 GMC Sierra 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 P133A 2018 GMC Sierra - Cylinder 3 Glow Plug Offset Exceeded Learning Limit - AutoCodes.com — P133A 2018 GMC Sierra Code - Cylinder 3 Glow Plug Offset Exceeded Learning Limit

What does this mean?

What are the Possible Causes of the DTC P133A 2018 GMC Sierra?

Perform Glow Plug Learn procedure
Faulty Glow Plug 3
Glow Plug 3 harness is open or shorted
Glow Plug 3 circuit poor electrical connection

How to Fix the DTC P133A 2018 GMC Sierra?

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 P133A 2018 GMC Sierra 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 P133A 2018 GMC Sierra code?

Need more information on how to fix the P133A 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P133A 2018 GMC Sierra 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 P133A 2018 GMC Sierra Code

1. What does the OBDII code P133A mean on a 2018 GMC Sierra?

P133A indicates that the glow plug offset for cylinder 3 has exceeded the learning limit, meaning the engine control module (ECM) has detected an issue with the glow plug's performance or calibration for that cylinder.

2. What are the symptoms of code P133A on a GMC Sierra?

Common symptoms include difficulty starting the engine in cold weather, rough idling, reduced engine performance, and the check engine light being illuminated.

3. What causes the P133A code to appear?

The most common causes are a faulty glow plug, poor electrical connection to the glow plug, a malfunctioning glow plug control module, or issues with the fuel injector or cylinder compression.

4. Can I drive my 2018 GMC Sierra with the P133A code active?

While the truck may still be drivable, ignoring the code can lead to increased engine wear, poor fuel efficiency, and difficulty starting in cold conditions. Itâ€™s best to address the issue promptly.

5. How is the P133A code diagnosed?

A technician will use a scan tool to confirm the code, inspect the glow plug, test the electrical connections, and evaluate the glow plug control module or other related components for faults.

6. How do I fix the P133A code on my 2018 GMC Sierra?

Repairs may include replacing the cylinder 3 glow plug, repairing wiring or connections, updating the ECM software, or replacing the glow plug control module if necessary.

7. How much does it cost to fix the P133A code?

The cost depends on the specific repair, but replacing a glow plug typically costs between $150 and $300, including parts and labor.

8. Can a P133A code be caused by a software issue?

Yes, outdated ECM software or improper calibration can sometimes cause the P133A code. A software update might be required to resolve the issue.

9. How can I prevent the P133A code from recurring?

Regular maintenance, such as inspecting glow plugs and their connections, ensuring proper fuel injector operation, and keeping the ECM software up to date, can help prevent this code.

10. Do I need special tools to diagnose or fix the P133A code?

Yes, diagnosing this code usually requires an OBDII scan tool capable of reading manufacturer-specific codes, as well as a multimeter to test electrical connections.