AutoCodes – Chevrolet – P18BC 2016 Chevrolet Silverado

P18BC 2016 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 2016 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.

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Code Popularity 213

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 P18BC 2016 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 2016 Chevrolet Silverado - Internal Mode Switch 'C' Circuit Stuck Off Invalid Voltage Range - AutoCodes.com — P18BC 2016 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 2016 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 2016 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 2016 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 2016 Chevrolet Silverado code?

Need more information on how to fix the P18BC 2016 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 P18BC 2016 Chevrolet Silverado Code

1. What does OBDII code P18BC mean for a 2016 Chevrolet Silverado?

The code P18BC for a 2016 Chevrolet Silverado refers to the Internal Mode Switch 'C' Circuit Stuck Off Invalid Voltage Range.

2. What are the common symptoms of OBDII code P18BC in a 2016 Chevrolet Silverado?

Common symptoms of code P18BC may include issues with shifting gears, the transmission not engaging correctly, or the vehicle going into "limp mode."

3. What can cause OBDII code P18BC to trigger in a 2016 Chevrolet Silverado?

Potential causes of code P18BC include a faulty internal mode switch, wiring problems, a defective transmission control module, or issues with the vehicle's electrical system.

4. How serious is OBDII code P18BC in a 2016 Chevrolet Silverado?

Code P18BC can affect the drivability of the vehicle and potentially lead to transmission-related issues. It is recommended to address this code promptly to prevent further damage.

5. How can I diagnose OBDII code P18BC in my 2016 Chevrolet Silverado?

Diagnosing code P18BC typically involves using a scan tool to read the code, checking the internal mode switch and related wiring for faults, and testing the transmission control module.

6. Can I drive my 2016 Chevrolet Silverado with OBDII code P18BC?

It is not advisable to drive your vehicle with an unresolved P18BC code, as it can lead to transmission problems and potentially impact your safety on the road.

7. What repairs are typically needed to fix OBDII code P18BC in a 2016 Chevrolet Silverado?

Repairing code P18BC may involve replacing the internal mode switch, repairing or replacing damaged wiring, reprogramming the transmission control module, or addressing any underlying electrical issues.

8. How much does it cost to fix OBDII code P18BC in a 2016 Chevrolet Silverado?

The cost of fixing code P18BC can vary depending on the specific repairs needed and labor costs. It's recommended to consult a professional mechanic for an accurate estimate.

9. Can I reset OBDII code P18BC in my 2016 Chevrolet Silverado myself?

While you can clear the code with an OBDII scanner, it's crucial to address the underlying issue causing the code to prevent it from reoccurring.

10. Will OBDII code P18BC cause my 2016 Chevrolet Silverado to fail an emissions test?

Code P18BC can potentially cause your vehicle to fail an emissions test, as it indicates a problem with the transmission system that can affect emissions control. It's best to address the issue before undergoing an emissions test.