AutoCodes – Chevrolet – P18B7 2015 Chevrolet Silverado

P18B7 2015 Chevrolet Silverado Code - Internal Mode Switch 'C' Circuit Shorted

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: P18B7 2015 Chevrolet Silverado indicates Internal Mode Switch 'C' Circuit Shorted.
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 464

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 P18B7 2015 Chevrolet Silverado 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 C signal circuit voltage is between 0.966–1.68 V, for 1.75 s.

OBDII Code P18B7 2015 Chevrolet Silverado - Internal Mode Switch 'C' Circuit Shorted - AutoCodes.com — P18B7 2015 Chevrolet Silverado Code - Internal Mode Switch 'C' Circuit Shorted

What does this mean?

What are the Possible Causes of the DTC P18B7 2015 Chevrolet Silverado?

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 P18B7 2015 Chevrolet Silverado?

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 P18B7 2015 Chevrolet Silverado 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 P18B7 2015 Chevrolet Silverado code?

Need more information on how to fix the P18B7 2015 Chevrolet Silverado 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 P18B7 2015 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P18B7 in a 2015 Chevrolet Silverado?

The common symptoms of OBDII code P18B7, Internal Mode Switch 'C' Circuit Shorted, in a 2015 Chevrolet Silverado may include issues with shifting gears, the transmission not engaging properly, or the vehicle going into limp mode.

2. What can cause the Internal Mode Switch 'C' Circuit Shorted code in a 2015 Chevrolet Silverado?

Possible causes of the Internal Mode Switch 'C' Circuit Shorted code in a 2015 Chevrolet Silverado include a faulty internal mode switch, damaged wiring or connectors, or a malfunctioning transmission control module.

3. How serious is the P18B7 code in a 2015 Chevrolet Silverado?

The P18B7 code, indicating an Internal Mode Switch 'C' Circuit Shorted, should be addressed promptly as it can lead to transmission issues and potentially unsafe driving conditions. It is advised to diagnose and repair the problem as soon as possible.

4. Can I continue driving my 2015 Chevrolet Silverado with the P18B7 trouble code?

It is not recommended to continue driving your 2015 Chevrolet Silverado with the P18B7 code present, as it can cause further damage to the transmission. It is best to address the issue and have it repaired by a qualified mechanic.

5. How can I diagnose the Internal Mode Switch 'C' Circuit Shorted code in my 2015 Chevrolet Silverado?

Diagnosing the P18B7 code in a 2015 Chevrolet Silverado typically involves using a scan tool to retrieve the trouble codes, inspecting the internal mode switch and its circuit for damage, and checking the wiring and connectors for any issues.

6. What are some repair tips for fixing the P18B7 code in a 2015 Chevrolet Silverado?

Repair tips for addressing the P18B7 code in a 2015 Chevrolet Silverado may include inspecting and repairing any damaged wiring or connectors, replacing the internal mode switch if necessary, and clearing the trouble codes after completing the repairs.

7. Can I reset the P18B7 trouble code in my 2015 Chevrolet Silverado without fixing the underlying issue?

While you can clear the trouble codes using a scan tool, it is not recommended to reset the P18B7 code in your 2015 Chevrolet Silverado without addressing the underlying issue. The problem may persist and lead to further complications if not properly repaired.

8. How much does it cost to repair the Internal Mode Switch 'C' Circuit Shorted code in a 2015 Chevrolet Silverado?

The cost of repairing the Internal Mode Switch 'C' Circuit Shorted code in a 2015 Chevrolet Silverado can vary depending on the extent of the damage, parts needed for replacement, and labor rates. It is advisable to consult with a mechanic for an accurate estimate.

9. Is the P18B7 trouble code covered under warranty for a 2015 Chevrolet Silverado?

If your 2015 Chevrolet Silverado is still under warranty, the repair for the P18B7 trouble code may be covered depending on the terms of your warranty. It is recommended to check with your dealership or refer to your warranty documentation for more information.

10. Can a DIY enthusiast fix the P18B7 code in a 2015 Chevrolet Silverado?

While some DIY enthusiasts may have the skills to diagnose and repair the P18B7 code in a 2015 Chevrolet Silverado, it is a complex issue related to the transmission system. For safety and proper repair, it is best to consult with a professional mechanic specializing in transmission repairs.