AutoCodes – Chevrolet – P18C3 2016 Chevrolet Silverado

P18C3 2016 Chevrolet Silverado Code - Internal Mode Switch 'S' Circuit Stuck On 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: P18C3 2016 Chevrolet Silverado indicates Internal Mode Switch 'S' Circuit Stuck On 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 211

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 P18C3 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 has an internal mode switch S signal circuit has an invalid voltage range of 0.70 – 0.96 V, for 2.7 s.

OBDII Code P18C3 2016 Chevrolet Silverado - Internal Mode Switch 'S' Circuit Stuck On Invalid Voltage Range - AutoCodes.com — P18C3 2016 Chevrolet Silverado Code - Internal Mode Switch 'S' Circuit Stuck On Invalid Voltage Range

What does this mean?

What are the Possible Causes of the DTC P18C3 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 P18C3 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 P18C3 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 P18C3 2016 Chevrolet Silverado code?

Need more information on how to fix the P18C3 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 P18C3 2016 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P18C3 in a 2016 Chevrolet Silverado?

The common symptoms of code P18C3 include issues with shifting gears, difficulty engaging specific gears, and the check engine light illuminating on the dashboard.

2. What does the OBDII code P18C3 'Internal Mode Switch 'S' Circuit Stuck On Invalid Voltage Range' indicate in a 2016 Chevrolet Silverado?

This code indicates a problem with the internal mode switch 'S' circuit in the transmission range sensor, specifically that it is stuck in an invalid voltage range.

3. What are the possible causes of the Internal Mode Switch 'S' Circuit Stuck On Invalid Voltage Range code in a 2016 Chevrolet Silverado?

Possible causes of this code include a faulty internal mode switch, damaged wiring or connectors in the circuit, or issues with the transmission range sensor.

4. How can I diagnose the cause of OBDII code P18C3 in my 2016 Chevrolet Silverado?

Diagnosing this code typically involves using a diagnostic scanner to read the code, checking the wiring and connectors for damage, and testing the internal mode switch and transmission range sensor for proper functionality.

5. Can I continue driving my 2016 Chevrolet Silverado with OBDII code P18C3?

It is not recommended to continue driving with this code present, as it can lead to transmission issues and potentially cause further damage if left unresolved.

6. How can I repair OBDII code P18C3 in my 2016 Chevrolet Silverado?

Repairing this code may involve replacing the internal mode switch, repairing damaged wiring or connectors, or recalibrating the transmission range sensor to resolve the voltage range issue.

7. Is it safe to clear the OBDII code P18C3 in my 2016 Chevrolet Silverado without addressing the underlying issue?

Clearing the code without addressing the underlying issue is not recommended, as the problem will likely reoccur, and unresolved transmission issues can affect the vehicle's performance and safety.

8. Can a DIY enthusiast fix OBDII code P18C3 in a 2016 Chevrolet Silverado?

While some basic diagnostics and repairs can be done by a DIY enthusiast, addressing complex transmission-related issues like this code may require specialized tools and expertise best handled by a professional mechanic.

9. How much does it cost to repair OBDII code P18C3 in a 2016 Chevrolet Silverado?

The cost of repairing this code can vary depending on the underlying cause and the labor rates of the repair shop. Replacing the internal mode switch or addressing wiring issues may cost a few hundred dollars.

10. How can I prevent OBDII code P18C3 from appearing in my 2016 Chevrolet Silverado in the future?

Regular maintenance, including checking the transmission system for any signs of wear or damage, can help prevent issues like code P18C3 from occurring in the future.