AutoCodes – Chevrolet – P18BC 2014 Chevrolet Silverado

P18BC 2014 Chevrolet Silverado Code - Internal Mode Switch 'C' 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: P18BC 2014 Chevrolet Silverado indicates Internal Mode Switch 'C' 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 234

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
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P18BC 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 C signal circuit has an invalid voltage range of 1.68 – 2.38 V, for 2.7 s.

OBDII Code P18BC 2014 Chevrolet Silverado - Internal Mode Switch 'C' Circuit Stuck Off Invalid Voltage Range - AutoCodes.com — P18BC 2014 Chevrolet Silverado Code - Internal Mode Switch 'C' Circuit Stuck Off Invalid Voltage Range

What does this mean?

What are the Possible Causes of the DTC P18BC 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 P18BC 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 P18BC 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 P18BC 2014 Chevrolet Silverado code?

Need more information on how to fix the P18BC 2014 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P18BC 2014 Chevrolet Silverado code diagnosed by a professional: Find a repair shop in your area

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 P18BC 2014 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P18BC in a 2014 Chevrolet Silverado?

The common symptoms of code P18BC include issues with shifting gears, rough or delayed gear changes, and the inability to switch between gears smoothly.

2. What does the OBDII code P18BC 'Internal Mode Switch 'C' Circuit Stuck Off Invalid Voltage Range' mean for a 2014 Chevrolet Silverado?

This code indicates that the transmission control module has detected an incorrect voltage range in the circuit related to the internal mode switch 'C'.

3. What are the possible causes of OBDII code P18BC in a 2014 Chevrolet Silverado?

Possible causes of code P18BC include a faulty internal mode switch, damaged wiring or connectors in the circuit, a malfunctioning transmission control module, or low voltage in the system.

4. How can I diagnose OBDII code P18BC in my 2014 Chevrolet Silverado?

Diagnosing code P18BC typically involves using a scan tool to retrieve the code, checking the wiring and connectors for any visible damage, testing the internal mode switch, and verifying the voltage levels in the circuit.

5. Can I still drive my 2014 Chevrolet Silverado with OBDII code P18BC?

It is not recommended to drive your vehicle with an active P18BC code, as it can lead to further transmission issues and potential safety hazards. It's best to address the problem promptly.

6. How should I repair OBDII code P18BC in my 2014 Chevrolet Silverado?

Repairing code P18BC may involve replacing the internal mode switch, repairing or replacing damaged wiring or connectors, resetting the transmission control module, and ensuring proper voltage levels in the circuit.

7. Is it necessary to reset the OBDII code P18BC after repairing my 2014 Chevrolet Silverado?

After repairing the underlying issue causing code P18BC, it is recommended to clear the code using a scan tool. This will reset the vehicle's system and turn off the check engine light.

8. Can a DIY enthusiast fix OBDII code P18BC in a 2014 Chevrolet Silverado?

While some aspects of diagnosing and repairing code P18BC can be tackled by a DIY enthusiast with the right tools and knowledge, complex transmission-related issues may require professional assistance.

9. Will ignoring OBDII code P18BC cause further damage to my 2014 Chevrolet Silverado?

Ignoring code P18BC can potentially lead to more severe transmission problems, decreased performance, and safety concerns. Addressing the issue promptly is crucial to prevent further damage.

10. How can I prevent OBDII code P18BC from occurring in my 2014 Chevrolet Silverado in the future?

Regular maintenance, such as checking the transmission system, inspecting wiring and connectors, and addressing any related issues promptly, can help prevent the recurrence of code P18BC in your Chevrolet Silverado.