AutoCodes – Chevrolet – P18B8 2014 Chevrolet Silverado

P18B8 2014 Chevrolet Silverado Code - Internal Mode Switch 'P' 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: P18B8 2014 Chevrolet Silverado indicates Internal Mode Switch 'P' 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 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 P18B8 2014 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 P signal circuit voltage is between 0.966–1.68 V, for 1.75 s.

OBDII Code P18B8 2014 Chevrolet Silverado - Internal Mode Switch 'P' Circuit Shorted - AutoCodes.com — P18B8 2014 Chevrolet Silverado Code - Internal Mode Switch 'P' Circuit Shorted

What does this mean?

What are the Possible Causes of the DTC P18B8 2014 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 P18B8 2014 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 P18B8 2014 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 P18B8 2014 Chevrolet Silverado code?

Need more information on how to fix the P18B8 2014 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 P18B8 2014 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P18B8 in a 2014 Chevrolet Silverado?

The common symptoms of code P18B8 "Internal Mode Switch 'P' Circuit Shorted" in a 2014 Chevrolet Silverado may include issues with shifting gears, the transmission not responding correctly, and the Check Engine light being illuminated.

2. What could cause the OBDII code P18B8 to trigger in a 2014 Chevrolet Silverado?

The P18B8 code in a 2014 Chevrolet Silverado is typically triggered by a short circuit in the internal mode switch 'P' circuit, which may be caused by damaged wiring, a faulty internal mode switch, or electrical issues.

3. How serious is the OBDII code P18B8 in a 2014 Chevrolet Silverado?

Code P18B8 should be addressed promptly as it can lead to erratic transmission behavior and potential safety concerns if left unresolved. It is recommended to diagnose and repair the issue to ensure proper operation of the transmission.

4. Can I continue driving my 2014 Chevrolet Silverado with OBDII code P18B8 present?

It is not advisable to continue driving the vehicle with code P18B8 active, as it can affect the transmission's performance and lead to further damage. It is recommended to address the issue as soon as possible.

5. How can I diagnose and repair OBDII code P18B8 in my 2014 Chevrolet Silverado?

Diagnosing and repairing code P18B8 may involve using a scan tool to identify the specific cause of the circuit short, inspecting wiring for damage, testing the internal mode switch, and replacing any faulty components as needed.

6. Is it possible to reset the OBDII code P18B8 in a 2014 Chevrolet Silverado without fixing the issue?

While you can clear the code with a scan tool, it is essential to address the underlying problem causing code P18B8. Simply clearing the code without fixing the root cause may result in the issue recurring.

7. How much does it typically cost to repair OBDII code P18B8 in a 2014 Chevrolet Silverado?

The cost of repairing code P18B8 can vary depending on the exact cause of the circuit short and the labor rates in your area. It is recommended to consult with a mechanic or dealership for an accurate estimate.

8. Can a DIY enthusiast fix OBDII code P18B8 in a 2014 Chevrolet Silverado?

While some DIY enthusiasts may have the skills to diagnose and repair code P18B8, it involves working with the vehicle's transmission system, which can be complex. It is advisable to have a professional technician handle the repair to ensure it is done correctly.

9. Will fixing OBDII code P18B8 improve the overall performance of my 2014 Chevrolet Silverado?

Addressing and resolving code P18B8 should help restore the proper operation of the transmission in your 2014 Chevrolet Silverado. Once repaired, the transmission should function correctly, improving the overall performance of the vehicle.

10. How long does it typically take to repair OBDII code P18B8 in a 2014 Chevrolet Silverado?

The time required to repair code P18B8 can vary based on the exact cause of the issue and the complexity of the repair. It is recommended to consult with a professional technician for a more accurate estimate of the repair timeline.