P1839 2016 GMC Sierra Code - Internal Mode Switch 'C' Circuit Low Voltage
Quick Answer
The P1839 diagnostic trouble code (DTC) for a 2016 GMC Sierra indicates an issue with the Internal Mode Switch 'C' Circuit, specifically low voltage. Common causes include Faulty Internal Mode Switch, Wiring or connector issues in the IMS circuit, Low battery voltage. 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 2016 GMC Sierra indicates Internal Mode Switch 'C' Circuit Low Voltage.
- Common causes
- Common causes include Faulty Internal Mode Switch, Wiring or connector issues in the IMS circuit, Low battery voltage.
- 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.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
Code P1839 2016 GMC Sierra Description
The P1839 diagnostic trouble code (DTC) for a 2016 GMC Sierra indicates an issue with the Internal Mode Switch 'C' Circuit, specifically low voltage. The Internal Mode Switch (IMS) is a component of the transmission range sensor that communicates the gear position to the vehicle's control module. In this case, the 'C' circuit refers to a specific part of the IMS system that is reporting low voltage.
Common Causes of P1839 2016 GMC Sierra
- Faulty Internal Mode Switch
- Wiring or connector issues in the IMS circuit
- Low battery voltage
- Transmission control module malfunction
- Software issues in the vehicle's control module
Symptoms of P1839 2016 GMC Sierra
- Delayed or harsh shifting
- Incorrect gear selection
- Transmission slipping
- Check Engine Light illuminated
- Reduced fuel efficiency
How to Fix P1839 2016 GMC Sierra
- Begin by conducting a thorough inspection of the Internal Mode Switch and its circuitry to identify any visible damage or loose connections.
- Test the voltage levels in the 'C' circuit to determine if it is indeed low, and address any voltage issues accordingly.
- Replace the Internal Mode Switch if it is found to be faulty, ensuring proper installation and calibration.
- Check and repair any damaged wiring or connectors in the IMS circuit.
- Clear the DTC and test drive the vehicle to confirm that the issue has been resolved.
Cost to Fix P1839 2016 GMC Sierra
The cost of repairing the Internal Mode Switch 'C' Circuit Low Voltage issue can vary depending on the extent of the problem and the specific repairs needed. In general, replacing the Internal Mode Switch and addressing any wiring issues can range from $200 to $500, including parts and labor. However, it is important to note that diagnostic time and labor rates at auto repair shops can vary, so it is advisable to check with local shops for a more accurate estimate. Keep in mind that rates may be higher at dealerships or in metropolitan areas, while independent shops may offer more affordable prices.
Need more information about the P1839 2016 GMC Sierra code?
Need more information on how to fix the P1839 2016 GMC Sierra code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P1839 2016 GMC Sierra code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P1839 2016 GMC Sierra Code
What does the OBDII code P1839 mean on a 2016 GMC Sierra?
P1839 indicates a low voltage issue in the Internal Mode Switch 'C' circuit, which is part of the transmission's range sensor system.
What are the common symptoms of code P1839 in a 2016 GMC Sierra?
Common symptoms include erratic transmission shifting, the inability to shift into certain gears, the transmission stuck in one gear, or the illumination of the check engine light.
What causes the P1839 code to appear?
The most common causes are faulty wiring or connectors in the Internal Mode Switch 'C' circuit, a failed internal mode switch (range sensor), or a problem with the transmission control module (TCM).
Can a bad battery cause the P1839 code?
Yes, a weak or failing battery can sometimes lead to low voltage issues that might trigger this code.
How do you diagnose the P1839 code on a 2016 GMC Sierra?
Diagnosis involves checking the wiring and connectors in the circuit for damage, testing the internal mode switch for proper operation, and verifying voltage and continuity in the circuit using a multimeter.
Can I drive my 2016 GMC Sierra with the P1839 code?
Driving with this code is not recommended, as it can lead to erratic shifting or further damage to the transmission system.
How much does it cost to repair the P1839 code on a 2016 GMC Sierra?
Repairs can range from $100 to $500, depending on whether the issue is a simple wiring fix or requires replacing the internal mode switch.
Will clearing the code fix the problem?
Clearing the code will only temporarily turn off the check engine light. The underlying issue causing the low voltage must be addressed to prevent the code from returning.
What tools are needed to troubleshoot the P1839 code?
You’ll need an OBDII scanner, a multimeter to test voltage and continuity, and possibly wiring diagrams for the transmission system.
Is the P1839 code related to other transmission codes?
Yes, it can be related to other transmission range sensor or internal mode switch codes, as they all involve the same system. Additional codes may provide further insight into the issue.
Discuss the causes and fixes for P1839 2016 GMC Sierra OBDII Code
Code P1839 2016 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.