AutoCodes – GMC – P1824 GMC

P1824 GMC 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 GMC 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 1,271

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

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

What does this mean?

What are the Possible Causes of the DTC P1824 GMC?

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 GMC?

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 GMC 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 GMC code?

Need more information on how to fix the P1824 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1824 GMC code diagnosed by a professional: Find a repair shop in your area

Information for Specific GMC Models

P1824 2014 GMC Sierra — Internal Mode Switch 'P' Circuit Low Voltage
P1824 2015 GMC Sierra — Internal Mode Switch 'P' Circuit Low Voltage
P1824 2016 GMC Sierra — Internal Mode Switch 'P' Circuit Low Voltage
P1824 2017 GMC Sierra — Internal Mode Switch 'P' Circuit Low Voltage
P1824 2018 GMC Sierra — Internal Mode Switch 'P' Circuit Low Voltage

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 GMC Code

1. What are common symptoms of OBDII code P1824 GMC (Internal Mode Switch 'P' Circuit Low Voltage)?

The common symptoms include issues with shifting gears, rough or erratic shifting, and the inability to shift out of a particular gear.

2. What causes the OBDII code P1824 GMC to trigger?

The code is typically triggered by a malfunction in the internal mode switch (IMS) 'P' circuit, which may be caused by a faulty IMS, damaged wiring, or a poor electrical connection.

3. How can I diagnose the OBDII code P1824 GMC?

Diagnosing this code usually involves using a scan tool to retrieve the code from the vehicle's computer, checking the IMS and related components for damage or wear, and testing the circuit for proper voltage and continuity.

4. What are the possible repair options for OBDII code P1824 GMC?

Repair options may include replacing the internal mode switch, repairing or replacing damaged wiring or connectors, and clearing the code from the vehicle's computer.

5. Can I drive my vehicle with the OBDII code P1824 GMC present?

It is not recommended to drive your vehicle with this code present, as it can lead to further transmission issues and potentially cause damage to the transmission system.

6. How urgent is it to address the OBDII code P1824 GMC?

It is important to address this code promptly to prevent further damage to the transmission system and ensure the safe operation of your vehicle.

7. Is the OBDII code P1824 GMC easy to repair at home?

Depending on your experience and access to tools, repairing this code at home may be possible. However, it is recommended to consult a professional mechanic for accurate diagnosis and repair.

8. Can a low battery voltage cause the OBDII code P1824 GMC to trigger?

Yes, low battery voltage or electrical issues in the vehicle can affect the internal mode switch 'P' circuit and trigger the P1824 code.

9. How much does it typically cost to repair the OBDII code P1824 GMC?

The cost of repairing this code can vary depending on the extent of the issue, the parts needed, and the labor rates of the repair shop. It's best to obtain quotes from local mechanics for an accurate estimate.

10. How can I prevent the OBDII code P1824 GMC from reoccurring?

Regularly maintaining your vehicle, checking for wiring issues, and addressing any transmission-related problems promptly can help prevent the recurrence of the P1824 code.