P279C 2014 GMC Sierra Code - Four Wheel Drive Neutral Range Performance
Quick Answer
The Engine Control Module (ECM) uses the following two ways to determine if the transfer case is in 4WD Low, 4WD High, or Neutral. Common causes include Reprogram Engine Control Module (ECM), Faulty Engine Control Module, Engine Control Module 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
- P279C 2014 GMC Sierra indicates Four Wheel Drive Neutral Range Performance.
- Common causes
- Common causes include Reprogram Engine Control Module (ECM), Faulty Engine Control Module, Engine Control Module 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.
Code P279C 2014 GMC Sierra Description
1. The first way is to compare the transmission output speed sensor to the transfer case output speed sensor in order to calculate the transfer case range.
2. The second way is to use a LAN message sent by the transfer case shift control module to the ECM.
The ECM uses this message to determine motor torque required and transmission shifting.
The internal fault detection is handled inside the control module. No external circuit diagnosis is involved.
If the first way and second way of determining transfer case range do not match while in 4WD Low, 4WD High or Neutral, then the Diagnostic Trouble Code (DTC) is set.
What are the Possible Causes of the DTC P279C 2014 GMC Sierra?
- Reprogram Engine Control Module (ECM)
- Faulty Engine Control Module
- Engine Control Module harness is open or shorted
- Engine Control Module circuit poor electrical connection
- Transmission internal mechanical problems
How to Fix the DTC P279C 2014 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 is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P279C 2014 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 P279C 2014 GMC Sierra code?
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Frequently Asked Questions about P279C 2014 GMC Sierra Code
1. What does the OBDII code P279C mean on a 2014 GMC Sierra?
P279C indicates an issue with the Four Wheel Drive Neutral Range Performance, meaning the transfer case control module has detected a problem with the neutral range operation.
2. What are the common symptoms of the P279C code on a GMC Sierra?
Symptoms include the "Service 4WD" warning light, difficulty shifting into or out of neutral range, and possible inoperability of the four-wheel-drive system.
3. What causes the P279C code on a 2014 GMC Sierra?
Common causes include a faulty transfer case motor, wiring issues, transfer case sensor failure, or damaged components inside the transfer case.
4. Can driving with the P279C code cause further damage?
Yes, continuing to drive with this code can lead to additional wear on the transfer case or drivetrain components, especially if the four-wheel-drive system malfunctions.
5. How is the P279C code diagnosed?
Technicians will use a scan tool to verify the code, inspect the transfer case motor and sensors, check wiring and connectors, and test the transfer case control module.
6. Can a software issue cause the P279C code?
Yes, outdated or corrupted software in the transfer case control module can sometimes trigger this code and may require a software update or reprogramming.
7. What is the most common fix for the P279C code?
The most common fix is replacing the transfer case shift motor or repairing damaged wiring connected to the transfer case system.
8. How much does it cost to repair a P279C code on a GMC Sierra?
Repair costs vary, but replacing a transfer case motor can range from $300 to $600, while wiring repairs or sensor replacements may cost less.
9. Can I clear the P279C code without fixing the problem?
Clearing the code without addressing the underlying issue will likely result in the code returning and potentially worsening the problem.
10. Is the P279C code related to the four-wheel-drive shift buttons?
Yes, a faulty transfer case control module or wiring issue can cause problems with the four-wheel-drive shift buttons, leading to this code.
Discuss the causes and fixes for P279C 2014 GMC Sierra OBDII Code
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