P1339 2018 GMC Sierra Code - Cylinder 2 Glow Plug Offset Exceeded Learning Limit
Quick Answer
The diagnostic trouble code P1339 in a 2018 GMC Sierra indicates that the Engine Control Module (ECM) has detected that the offset for the glow plug in cylinder 2 has exceeded the learning limit. Common causes include Faulty glow plug in cylinder 2, Wiring issues related to the glow plug circuit, Malfunctioning glow plug control module. 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
- P1339 2018 GMC Sierra indicates Cylinder 2 Glow Plug Offset Exceeded Learning Limit.
- Common causes
- Common causes include Faulty glow plug in cylinder 2, Wiring issues related to the glow plug circuit, Malfunctioning glow plug control module.
- 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 P1339 2018 GMC Sierra Description
The diagnostic trouble code P1339 in a 2018 GMC Sierra indicates that the Engine Control Module (ECM) has detected that the offset for the glow plug in cylinder 2 has exceeded the learning limit. Glow plugs are essential components in diesel engines, as they help heat the combustion chamber for easier starting in cold conditions. When the glow plug offset exceeds the learning limit, it means that the ECM is unable to control the glow plug's operation effectively, which can lead to issues with starting the engine, reduced fuel efficiency, and increased emissions.
Common Causes of P1339 2018 GMC Sierra
- Faulty glow plug in cylinder 2
- Wiring issues related to the glow plug circuit
- Malfunctioning glow plug control module
- ECM software or hardware issues
- Poor quality fuel or contaminated fuel filter
Symptoms of P1339 2018 GMC Sierra
- Hard starting, especially in cold weather
- Rough idling or stalling
- Decreased power output
- Increased fuel consumption
- Illumination of the check engine light
How to Fix P1339 2018 GMC Sierra
- Begin by diagnosing the specific cause of the P1339 code using a diagnostic scanner to pinpoint the issue accurately.
- Inspect the glow plug in cylinder 2 for proper operation and replace it if necessary.
- Check the wiring and connections in the glow plug circuit for any damage or corrosion, repairing or replacing as needed.
- Test the glow plug control module to ensure it is functioning correctly, replacing it if found to be faulty.
- Clear the code from the ECM's memory and perform a test drive to verify that the issue has been resolved.
Cost to Fix P1339 2018 GMC Sierra
The typical repair costs for addressing the P1339 code in a 2018 GMC Sierra can vary depending on the specific cause of the issue. In general, replacing a glow plug can cost between $50 and $150 per plug, while diagnosing and repairing wiring or control module issues may range from $100 to $500. Labor costs at auto repair shops can vary between $80 and $150 per hour, so the total repair bill could range from $200 to $800 or more. It's advisable to consult with a trusted mechanic or dealership for a more accurate estimate based on the specific circumstances of your vehicle.
Tech Notes for P1339 2018 GMC Sierra
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Frequently Asked Questions about P1339 2018 GMC Sierra Code
What does OBDII code P1339 mean on a 2018 GMC Sierra?
P1339 indicates that the Cylinder 2 Glow Plug Offset has exceeded the learning limit, meaning the engine control module (ECM) has detected an issue with the glow plug operation or its calibration on cylinder 2.
What are the symptoms of code P1339 on a 2018 GMC Sierra?
Common symptoms include difficulty starting in cold weather, increased exhaust smoke during startup, reduced engine performance, and an illuminated check engine light.
What causes the P1339 code to appear on a 2018 GMC Sierra?
Potential causes include a faulty glow plug in cylinder 2, damaged or corroded wiring or connectors, a malfunctioning glow plug control module, or incorrect calibration in the ECM.
Can I drive my 2018 GMC Sierra with a P1339 code?
While it may still be drivable, the vehicle may experience starting issues or reduced performance, especially in cold weather. Prolonged driving without addressing the issue could lead to further engine complications.
How do I diagnose the P1339 code on a 2018 GMC Sierra?
Diagnosis involves checking the glow plug in cylinder 2 for damage, testing the wiring and connectors for continuity, inspecting the glow plug control module, and verifying ECM calibration.
How can I fix the P1339 code on my 2018 GMC Sierra?
Repairs may include replacing the faulty glow plug in cylinder 2, repairing damaged wiring or connectors, replacing the glow plug control module, or reprogramming the ECM if calibration is incorrect.
How much does it cost to repair the P1339 code on a 2018 GMC Sierra?
Repair costs can vary, but replacing a glow plug typically costs $100–$200, while addressing wiring issues or replacing a control module may cost more depending on labor rates and parts.
What tools are needed to diagnose and repair the P1339 code?
You’ll need an OBDII scanner, a multimeter to test continuity, and potentially a glow plug removal tool. In some cases, specialized software may be required to reprogram the ECM.
Can a faulty glow plug cause long-term damage to my 2018 GMC Sierra?
Yes, a faulty glow plug can lead to poor combustion, increased emissions, and strain on the engine, especially in cold conditions, potentially causing further damage if not addressed.
Is the P1339 code specific to GMC vehicles?
No, while P1339 is common in GMC and Chevrolet diesel vehicles, it can appear in other vehicles with similar systems, but the definition and diagnostic steps may vary.
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