P1838 2016 GMC Sierra Code - Internal Mode Switch 'A' Circuit High Voltage
Quick Answer
The P1838 diagnostic trouble code (DTC) for a 2016 GMC Sierra indicates a problem with the Internal Mode Switch 'A' Circuit High Voltage. Common causes include Faulty internal mode switch, Damaged wiring or connectors in the IMS circuit, Corrosion or moisture in the IMS connector. 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
- P1838 2016 GMC Sierra indicates Internal Mode Switch 'A' Circuit High Voltage.
- Common causes
- Common causes include Faulty internal mode switch, Damaged wiring or connectors in the IMS circuit, Corrosion or moisture in the IMS connector.
- 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 P1838 2016 GMC Sierra Description
The P1838 diagnostic trouble code (DTC) for a 2016 GMC Sierra indicates a problem with the Internal Mode Switch 'A' Circuit High Voltage. This code is related to the transmission range sensor, also known as the internal mode switch (IMS). The IMS is responsible for communicating the gear position (Park, Reverse, Neutral, Drive, etc.) to the vehicle's transmission control module (TCM).
Common Causes of P1838 2016 GMC Sierra
- Faulty internal mode switch
- Damaged wiring or connectors in the IMS circuit
- Corrosion or moisture in the IMS connector
- Issues with the transmission control module (TCM)
- Electrical problems in the vehicle's wiring harness
Symptoms of P1838 2016 GMC Sierra
- Erratic shifting behavior
- Harsh or delayed shifting
- Inability to shift gears
- Check Engine Light illuminated
- Reduced fuel efficiency
How to Fix P1838 2016 GMC Sierra
- Begin by conducting a thorough inspection of the IMS circuit, wiring, and connectors to identify any visible damage or corrosion.
- Test the internal mode switch using a multimeter to check for proper voltage and continuity.
- If the IMS is faulty, it will need to be replaced. This typically involves removing the transmission pan to access the switch.
- Clear the DTC from the TCM's memory using a scan tool.
- Test drive the vehicle to ensure that the shifting issues have been resolved and that the code does not return.
Cost to Fix P1838 2016 GMC Sierra
The cost of repairing a P1838 code on a 2016 GMC Sierra can vary depending on the extent of the issue and the specific parts needed. Typically, the cost of replacing an internal mode switch can range from $150 to $300, including parts and labor. Additional costs may be incurred for diagnostic testing and any other necessary repairs. It's important to factor in the specific diagnosis time and labor rates at your local auto repair shop when estimating the total cost of this repair.
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Frequently Asked Questions about P1838 2016 GMC Sierra Code
1. What are the common symptoms of OBDII code P1838 in a 2016 GMC Sierra?
- Common symptoms include issues with shifting gears, erratic behavior of the transmission, and the check engine light being illuminated.
2. What does the OBDII code P1838 'Internal Mode Switch 'A' Circuit High Voltage' mean in a 2016 GMC Sierra?
- This code indicates that there is a high voltage condition detected in the internal mode switch 'A' circuit of the transmission range sensor.
3. What are the possible causes of OBDII code P1838 in a 2016 GMC Sierra?
- Possible causes of this code include a faulty internal mode switch, damaged wiring or connectors in the circuit, or a malfunctioning transmission range sensor.
4. How can I diagnose OBDII code P1838 in a 2016 GMC Sierra?
- Diagnosing this code typically involves using a scan tool to retrieve the specific code, checking the internal mode switch and related wiring for any visible damage, and testing the transmission range sensor.
5. Can I still drive my 2016 GMC Sierra with OBDII code P1838 present?
- It is not recommended to continue driving the vehicle with this code present, as it can lead to further transmission issues and potentially cause damage if not addressed promptly.
6. How can I repair OBDII code P1838 in a 2016 GMC Sierra?
- Repairing this code usually involves replacing the internal mode switch, repairing any damaged wiring or connectors, or replacing the transmission range sensor if necessary.
7. Is it possible to reset OBDII code P1838 in a 2016 GMC Sierra without fixing the underlying issue?
- While you can clear the code with a scan tool, it is important to address the underlying issue causing the code to prevent further transmission problems.
8. Are there any DIY tips for troubleshooting OBDII code P1838 in a 2016 GMC Sierra?
- DIY tips include checking the transmission fluid level, inspecting the wiring and connectors for any visible damage, and ensuring all connections are secure.
9. How much does it typically cost to repair OBDII code P1838 in a 2016 GMC Sierra?
- The cost of repairing this code can vary depending on the specific issue, but it may range from $200 to $500 for parts and labor.
10. Can a mechanic easily fix OBDII code P1838 in a 2016 GMC Sierra?
- A qualified mechanic should be able to diagnose and repair this code efficiently, ensuring proper functioning of the transmission system in your GMC Sierra.
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