AutoCodes – GMC – P18BE 2014 GMC Sierra

P18BE 2014 GMC Sierra Code - Internal Mode Switch 'S' Circuit Stuck Off Invalid Voltage Range

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: P18BE 2014 GMC Sierra indicates Internal Mode Switch 'S' Circuit Stuck Off Invalid Voltage Range.
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 189

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 P18BE 2014 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 has an invalid voltage range of 1.68 – 2.38 V, for 2.7 s.

OBDII Code P18BE 2014 GMC Sierra - Internal Mode Switch 'S' Circuit Stuck Off Invalid Voltage Range - AutoCodes.com — P18BE 2014 GMC Sierra Code - Internal Mode Switch 'S' Circuit Stuck Off Invalid Voltage Range

What does this mean?

What are the Possible Causes of the DTC P18BE 2014 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 P18BE 2014 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 P18BE 2014 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 P18BE 2014 GMC Sierra code?

Need more information on how to fix the P18BE 2014 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 P18BE 2014 GMC Sierra Code

1. What are the common symptoms of OBDII code P18BE in a 2014 GMC Sierra?

The common symptoms of OBDII code P18BE include issues with shifting gears, the vehicle staying in one gear, difficulty shifting, and the check engine light being illuminated.

2. What does the OBDII code P18BE in a 2014 GMC Sierra indicate?

OBDII code P18BE indicates a problem with the Internal Mode Switch 'S' Circuit being stuck off due to an invalid voltage range.

3. What are the possible causes of OBDII code P18BE in a 2014 GMC Sierra?

The possible causes of OBDII code P18BE include a faulty internal mode switch, damaged wiring or connectors, low transmission fluid, or issues with the transmission control module.

4. How serious is the OBDII code P18BE in a 2014 GMC Sierra?

While the vehicle may still be operable with this code present, it is important to address the issue promptly to prevent further damage to the transmission system.

5. How can OBDII code P18BE in a 2014 GMC Sierra be diagnosed?

Diagnosing OBDII code P18BE typically involves using a scan tool to retrieve the code, checking the internal mode switch and wiring for faults, and testing the transmission control module for proper functioning.

6. Can OBDII code P18BE in a 2014 GMC Sierra be repaired at home?

Depending on the cause of the code, some repairs for OBDII code P18BE may be possible at home, such as replacing the internal mode switch or repairing damaged wiring. However, more complex issues may require professional diagnosis and repair.

7. How much does it cost to fix OBDII code P18BE in a 2014 GMC Sierra?

The cost to fix OBDII code P18BE can vary depending on the root cause of the issue. Simple fixes like replacing the internal mode switch may cost a couple of hundred dollars, while more extensive repairs could cost upwards of a thousand dollars.

8. Are there any preventive measures to avoid OBDII code P18BE in a 2014 GMC Sierra?

To help prevent OBDII code P18BE, it is recommended to perform regular maintenance on the vehicle, including checking transmission fluid levels, inspecting wiring harnesses for damage, and addressing any transmission issues promptly.

9. Can driving with OBDII code P18BE in a 2014 GMC Sierra cause further damage?

Continuing to drive with OBDII code P18BE present may cause further damage to the transmission system over time. It is best to address the issue as soon as possible to avoid more costly repairs.

10. Is it safe to ignore OBDII code P18BE in a 2014 GMC Sierra?

While the vehicle may still be operational with this code present, ignoring OBDII code P18BE can lead to potential transmission problems and possible safety hazards. It is recommended to address the issue promptly.