P1839 2014 GMC Sierra Code - Internal Mode Switch 'C' Circuit Low Voltage
Quick Answer
The internal mode switch indicates the Transmission Control Module (TCM) which gear position the vehicle operator has selected. Common causes include Faulty Transmission Internal Mode Switch, Transmission Internal Mode Switch harness is open or shorted, Transmission Internal Mode Switch circuit poor electrical connection. 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
- P1839 2014 GMC Sierra indicates Internal Mode Switch 'C' Circuit Low Voltage.
- Common causes
- Common causes include Faulty Transmission Internal Mode Switch, Transmission Internal Mode Switch harness is open or shorted, Transmission Internal Mode Switch circuit poor electrical connection.
- 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 P1839 2014 GMC Sierra Description
What are the Possible Causes of the DTC P1839 2014 GMC Sierra?
- Faulty Transmission Internal Mode Switch
- Transmission Internal Mode Switch harness is open or shorted
- Transmission Internal Mode Switch circuit poor electrical connection
- Faulty Transmission Control Module (TCM)
How to Fix the DTC P1839 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 P1839 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 P1839 2014 GMC Sierra code?
Need more information on how to fix the P1839 2014 GMC Sierra code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P1839 2014 GMC Sierra code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P1839 2014 GMC Sierra Code
1. What does the OBDII code P1839 mean on a 2014 GMC Sierra?
P1839 indicates an issue with the Internal Mode Switch 'C' Circuit, specifically detecting a low voltage condition.
2. What are the common symptoms of a P1839 code on a 2014 GMC Sierra?
Symptoms may include check engine light illumination, transmission stuck in one gear, erratic shifting, or failure to engage certain gears.
3. What causes the P1839 code on a GMC Sierra?
The code is often caused by a faulty internal mode switch, damaged wiring, poor electrical connections, or low voltage in the circuit.
4. How do you diagnose a P1839 code on a 2014 GMC Sierra?
Diagnosis involves checking the internal mode switch, inspecting wires and connectors for damage or corrosion, and testing voltage levels in the circuit with a multimeter.
5. Can a P1839 code affect the drivability of a 2014 GMC Sierra?
Yes, it can cause issues like stuck gears or erratic shifting, which may impact the vehicle's drivability.
6. Is the internal mode switch the same as the transmission range sensor?
Yes, the internal mode switch is also referred to as the transmission range sensor and is responsible for monitoring gear selection.
7. How is a P1839 code fixed on a GMC Sierra?
Repairs may include replacing the internal mode switch, repairing or replacing damaged wiring, or cleaning corroded connections in the circuit.
8. Can a low battery cause a P1839 code?
Yes, a weak or low battery can cause voltage issues in the circuit and trigger the P1839 code.
9. How much does it cost to repair a P1839 code on a 2014 GMC Sierra?
Repair costs vary but typically range from $200 to $400, depending on whether the internal mode switch or wiring needs replacement.
10. Can I drive my 2014 GMC Sierra with a P1839 code?
While the vehicle may still operate, driving with this code can lead to further transmission issues and should be addressed promptly.
Discuss the causes and fixes for P1839 2014 GMC Sierra OBDII Code
Code P1839 2014 GMC Sierra comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
