AutoCodes – GMC – P1824 2018 GMC Sierra

P1824 2018 GMC Sierra Code - Internal Mode Switch 'P' 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: P1824 2018 GMC Sierra indicates Internal Mode Switch 'P' 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.

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Code Popularity 278

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 P1824 2018 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 P signal circuit voltage is less than 0.7 V, for 1.75 s.

OBDII Code P1824 2018 GMC Sierra - Internal Mode Switch 'P' Circuit Low Voltage - AutoCodes.com — P1824 2018 GMC Sierra Code - Internal Mode Switch 'P' Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P1824 2018 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 P1824 2018 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 P1824 2018 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 P1824 2018 GMC Sierra code?

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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 P1824 2018 GMC Sierra Code

1. What are the common symptoms of OBDII code P1824 in a 2018 GMC Sierra?

- Common symptoms include issues with shifting gears, the transmission not responding correctly, and the Check Engine light being illuminated.

2. What causes the Internal Mode Switch 'P' Circuit Low Voltage error code (P1824) in a 2018 GMC Sierra?

- The code P1824 is typically triggered by a fault in the internal mode switch, wiring issues, or a defective internal mode switch.

3. How serious is the Internal Mode Switch 'P' Circuit Low Voltage OBDII code in a 2018 GMC Sierra?

- This code can affect the transmission's performance, so it is recommended to address it promptly to prevent further damage or safety issues.

4. Can I continue driving my 2018 GMC Sierra with the P1824 code present?

- It is not advisable to continue driving with the P1824 code active, as it can lead to transmission problems and potentially cause further damage.

5. How can I diagnose the Internal Mode Switch 'P' Circuit Low Voltage code in my 2018 GMC Sierra?

- Diagnosis typically involves using an OBDII scanner to retrieve the code, inspecting the internal mode switch and related wiring, and conducting voltage tests.

6. What are some DIY repair tips for resolving the P1824 code in a 2018 GMC Sierra?

- DIY repair tips may include checking and repairing wiring connections, replacing the internal mode switch if faulty, and clearing the code with an OBDII scanner.

7. Is it necessary to visit a mechanic for the Internal Mode Switch 'P' Circuit Low Voltage code in a 2018 GMC Sierra?

- While some DIY repairs are possible, it is recommended to consult a professional mechanic for a proper diagnosis and repair of the P1824 code.

8. How much does it cost to fix the P1824 code in a 2018 GMC Sierra?

- The cost of fixing the P1824 code can vary depending on the exact cause of the issue, but it may involve replacing the internal mode switch or repairing wiring, which can range from $200 to $500 or more.

9. Can resetting the OBDII code P1824 in a 2018 GMC Sierra make it go away permanently?

- Resetting the code may temporarily turn off the Check Engine light, but if the underlying issue causing the P1824 code is not addressed, it is likely to reappear.

10. How can I prevent the Internal Mode Switch 'P' Circuit Low Voltage code from recurring in my 2018 GMC Sierra?

- Regular maintenance, checking for loose or damaged wiring, and promptly addressing transmission issues can help prevent the reoccurrence of the P1824 code.