AutoCodes.com | All About OBDII Engine Codes
AutoCodes - GMC - P1841 GMC

P1841 GMC Code - Internal Mode Switch 'S' Circuit High Voltage

- Code Popularity: 1,336 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
Table of contents
Share on Facebook   Share on Twitter   Share on Linkedin

What are the Possible Causes of the DTC P1841 GMC?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • 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)
⚠ Does your GMC have Safety Recalls? → Check here

How to Fix the DTC P1841 GMC?

Review the 'Possible Causes' mentioned above and visually examine the corresponding wiring harness and connectors. Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.

Search for P1841 GMC Questions and Answers: Search here →

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1841 GMC code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

Code P1841 GMC 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 GMC - Internal Mode Switch 'S' Circuit High Voltage - AutoCodes.com
P1841 GMC Code - Internal Mode Switch 'S' Circuit High Voltage

Need More Information on the Code?

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

Need Help with the Code?

Get the P1841 GMC code diagnosed by a professional: Find a repair shop in your area

Code P1841 GMC comments

Help us improve AutoCodes.com. Leave a comment below or tell us if the information above helps you fix the code. What are the symptoms on your vehicle for the P1841 GMC code? Have you replaced any parts?
Any information is appreciated. Thanks