AutoCodes – Chevrolet – P18BB 2017 Chevrolet Silverado

P18BB 2017 Chevrolet Silverado Code - Internal Mode Switch 'B' 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: P18BB 2017 Chevrolet Silverado indicates Internal Mode Switch 'B' 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 224

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 P18BB 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 has an invalid voltage range of 1.68 – 2.38 V for 2.7 s.

OBDII Code P18BB 2017 Chevrolet Silverado - Internal Mode Switch 'B' Circuit Stuck Off Invalid Voltage Range - AutoCodes.com — P18BB 2017 Chevrolet Silverado Code - Internal Mode Switch 'B' Circuit Stuck Off Invalid Voltage Range

What does this mean?

What are the Possible Causes of the DTC P18BB 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 P18BB 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 P18BB 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 P18BB 2017 Chevrolet Silverado code?

Need more information on how to fix the P18BB 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 P18BB 2017 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P18BB on a 2017 Chevrolet Silverado?

The common symptoms of code P18BB include issues with shifting gears, the inability to start the vehicle, and the Check Engine light illuminating on the dashboard.

2. What does the Internal Mode Switch 'B' Circuit Stuck Off Invalid Voltage Range mean for a 2017 Chevrolet Silverado?

The code P18BB indicates a problem with the internal mode switch 'B' circuit in the transmission range sensor of a 2017 Chevrolet Silverado.

3. What are the possible causes of the Internal Mode Switch 'B' Circuit Stuck Off Invalid Voltage Range code on a 2017 Chevrolet Silverado?

Potential causes of code P18BB include a faulty internal mode switch, damaged wiring or connectors in the circuit, low transmission fluid levels, or a malfunctioning transmission control module.

4. How can I diagnose the Internal Mode Switch 'B' Circuit Stuck Off Invalid Voltage Range issue on my 2017 Chevrolet Silverado?

Diagnosing code P18BB may involve checking the transmission fluid levels, inspecting the internal mode switch and its circuit, testing the wiring and connectors for damage, and scanning the vehicle's computer for related error codes.

5. Can I drive my 2017 Chevrolet Silverado with the OBDII code P18BB present?

It is not recommended to drive your vehicle with the P18BB code active, as it can lead to transmission issues and potentially cause further damage. It's best to address the problem promptly.

6. How serious is the Internal Mode Switch 'B' Circuit Stuck Off Invalid Voltage Range fault on a 2017 Chevrolet Silverado?

The P18BB code should be taken seriously as it can affect the transmission's performance and reliability. Ignoring the issue may lead to more severe transmission problems over time.

7. What are some repair tips for fixing the OBDII code P18BB on a 2017 Chevrolet Silverado?

Repair tips for addressing code P18BB include checking and replacing the internal mode switch if necessary, repairing any damaged wiring or connectors, ensuring proper transmission fluid levels, and resetting the trouble codes.

8. Is it possible to reset the OBDII code P18BB on a 2017 Chevrolet Silverado without fixing the underlying issue?

While you can clear the trouble code temporarily, it is crucial to address the root cause of the problem to prevent the code from reappearing and causing further transmission issues.

9. How much does it typically cost to repair the Internal Mode Switch 'B' Circuit Stuck Off Invalid Voltage Range fault on a 2017 Chevrolet Silverado?

The cost of repairing code P18BB can vary depending on the exact cause of the issue, but it may involve expenses for parts, labor, and diagnostic services from a mechanic or dealership.

10. Can a DIY enthusiast fix the OBDII code P18BB on a 2017 Chevrolet Silverado themselves?

While some DIY enthusiasts may have the skills to address code P18BB, it is recommended to consult a professional mechanic or dealership for proper diagnosis and repair to ensure the issue is resolved correctly.