AutoCodes – GMC – P1841 2016 GMC Sierra

P1841 2016 GMC Sierra Code - Internal Mode Switch 'S' Circuit High 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: P1841 2016 GMC Sierra indicates Internal Mode Switch 'S' Circuit High 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.

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Code Popularity 167

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 23, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1841 2016 GMC Sierra Description

The internal mode switch indicates the Transmission Control Module (TCM) which gear position the vehicle operator has selected. The internal mode switch consists of 5 separate hall effect switches. Each hall effect switch is supplied with a 9 V reference circuit and a signal circuit from the TCM. Each signal circuit for each gear selector position will have either a voltage reading of 0.70–0.96 V indicating On or 1.68–2.38 V indicating Off. The voltage values on each internal mode switch circuit will change and are dependent on the position of the gear selector. The state of each internal mode switch A/B/C/P/S signal circuit is displayed on the scan tool. The Diagnostic Trouble Code (DTC) will be set when the TCM has detected the internal mode switch S signal circuit voltage is greater than 2.38 V, for 1.75 s.

OBDII Code P1841 2016 GMC Sierra - Internal Mode Switch 'S' Circuit High Voltage - AutoCodes.com — P1841 2016 GMC Sierra Code - Internal Mode Switch 'S' Circuit High Voltage

What does this mean?

What are the Possible Causes of the DTC P1841 2016 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 P1841 2016 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 P1841 2016 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 P1841 2016 GMC Sierra code?

Need more information on how to fix the P1841 2016 GMC Sierra code? Get Access to Factory Service Manuals

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P1841 2016 GMC Sierra Code

1. What are common symptoms of OBDII code P1841 on a 2016 GMC Sierra?

- Common symptoms include issues with shifting gears, rough or delayed gear changes, and potential stalling of the vehicle.

2. What does the Internal Mode Switch 'S' Circuit High Voltage code indicate in a 2016 GMC Sierra?

- This code indicates a problem with the internal mode switch, specifically a high voltage issue in the 'S' circuit.

3. What are possible causes of OBDII code P1841 on a 2016 GMC Sierra?

- Possible causes include a faulty internal mode switch, damaged wiring or connectors related to the switch, or a malfunctioning transmission control module.

4. How can I diagnose the Internal Mode Switch 'S' Circuit High Voltage issue on my 2016 GMC Sierra?

- Diagnosis typically involves using a scan tool to retrieve the trouble code, checking the internal mode switch for proper operation, and inspecting the wiring and connectors for any damage.

5. Can I continue driving my 2016 GMC Sierra with OBDII code P1841?

- It is not recommended to continue driving the vehicle with this code, as it can lead to further transmission issues and potential safety hazards.

6. How can I repair OBDII code P1841 on my 2016 GMC Sierra?

- Repair options include replacing the internal mode switch, repairing any damaged wiring or connectors, and resetting the trouble code with a scan tool.

7. Is it possible to reset OBDII code P1841 on a 2016 GMC Sierra without fixing the underlying issue?

- While you can clear the trouble code with a scan tool, the issue causing the code will likely persist and may lead to further problems if left unresolved.

8. Will OBDII code P1841 on a 2016 GMC Sierra cause the Check Engine light to illuminate?

- Yes, this code will typically trigger the Check Engine light to illuminate on the vehicle's dashboard.

9. How long does it take to repair the Internal Mode Switch 'S' Circuit High Voltage issue on a 2016 GMC Sierra?

- The repair time can vary depending on the exact cause of the issue, but it may take anywhere from a few hours to a full day to complete the necessary repairs.

10. Can a DIY enthusiast fix OBDII code P1841 on a 2016 GMC Sierra?

- While some DIY enthusiasts may have the skills to diagnose and repair this issue, it is recommended to consult a professional mechanic for proper diagnosis and repair to ensure the problem is addressed correctly.