AutoCodes – Chevrolet – P18B6 2017 Chevrolet Silverado

P18B6 2017 Chevrolet Silverado Code - Internal Mode Switch 'B' 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: P18B6 2017 Chevrolet Silverado indicates Internal Mode Switch 'B' 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 235

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 P18B6 2017 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 B signal circuit voltage is between 0.966–1.68 V, for 1.75 s.

OBDII Code P18B6 2017 Chevrolet Silverado - Internal Mode Switch 'B' Circuit Shorted - AutoCodes.com — P18B6 2017 Chevrolet Silverado Code - Internal Mode Switch 'B' Circuit Shorted

What does this mean?

What are the Possible Causes of the DTC P18B6 2017 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 P18B6 2017 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 P18B6 2017 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 P18B6 2017 Chevrolet Silverado code?

Need more information on how to fix the P18B6 2017 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 P18B6 2017 Chevrolet Silverado Code

1. What are common symptoms of the OBDII code P18B6 Internal Mode Switch 'B' Circuit Shorted in a 2017 Chevrolet Silverado?

The common symptoms include issues with shifting gears, erratic shifting patterns, and the transmission being stuck in one gear.

2. What causes the OBDII code P18B6 Internal Mode Switch 'B' Circuit Shorted in a 2017 Chevrolet Silverado?

The code is typically triggered by a short circuit in the internal mode switch 'B' circuit, which is part of the transmission control system.

3. How can I diagnose the OBDII code P18B6 in my 2017 Chevrolet Silverado?

Diagnosing the issue involves using an OBDII scanner to retrieve the trouble code, inspecting the internal mode switch circuit for shorts, and checking the wiring and connectors for any faults.

4. Can I still drive my 2017 Chevrolet Silverado with the P18B6 code present?

It is not recommended to drive the vehicle with the P18B6 code active, as it can lead to further damage to the transmission and affect the vehicle's performance.

5. How can I repair the Internal Mode Switch 'B' Circuit Shorted issue in my 2017 Chevrolet Silverado?

Repairing the issue involves locating and repairing the short circuit in the internal mode switch 'B' circuit, replacing any damaged wiring or connectors, and clearing the trouble code.

6. Is the OBDII code P18B6 Internal Mode Switch 'B' Circuit Shorted a common issue in the 2017 Chevrolet Silverado?

While not extremely common, this code can occur in the 2017 Chevrolet Silverado due to wiring issues, component failures, or electrical faults.

7. Can a DIY enthusiast fix the OBDII code P18B6 in a 2017 Chevrolet Silverado?

Depending on your skill level and access to tools, some DIY enthusiasts may be able to diagnose and repair the Internal Mode Switch 'B' Circuit Shorted issue, but it is recommended to consult a professional for complex repairs.

8. Will resetting the OBDII code P18B6 in my 2017 Chevrolet Silverado make it go away permanently?

Simply resetting the code will not fix the underlying issue causing the Internal Mode Switch 'B' Circuit Shorted problem. It is essential to diagnose and repair the root cause to prevent the code from reoccurring.

9. How much does it typically cost to repair the OBDII code P18B6 in a 2017 Chevrolet Silverado?

Repair costs can vary depending on the extent of the damage, parts needed for replacement, and labor rates. It is advisable to get a few quotes from reputable repair shops for an accurate estimate.

10. Can a faulty internal mode switch cause other transmission-related issues in a 2017 Chevrolet Silverado?

Yes, a faulty internal mode switch can cause other transmission-related issues such as harsh shifting, delayed engagement, or even transmission failure if not addressed promptly.