AutoCodes – Chevrolet – P18B5 2016 Chevrolet Silverado

P18B5 2016 Chevrolet Silverado Code - Internal Mode Switch 'A' 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: P18B5 2016 Chevrolet Silverado indicates Internal Mode Switch 'A' 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 279

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 P18B5 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 A signal circuit voltage is between 0.966–1.68 V, for 1.75 s.

OBDII Code P18B5 2016 Chevrolet Silverado - Internal Mode Switch 'A' Circuit Shorted - AutoCodes.com — P18B5 2016 Chevrolet Silverado Code - Internal Mode Switch 'A' Circuit Shorted

What does this mean?

What are the Possible Causes of the DTC P18B5 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 P18B5 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 P18B5 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 P18B5 2016 Chevrolet Silverado code?

Need more information on how to fix the P18B5 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 P18B5 2016 Chevrolet Silverado Code

1. What does the OBDII code P18B5 mean on a 2016 Chevrolet Silverado?

The P18B5 code indicates an "Internal Mode Switch 'A' Circuit Shorted," meaning there is a short circuit in the transmission's internal mode switch 'A' circuit.

2. What are the symptoms of the P18B5 code on a 2016 Chevrolet Silverado?

Common symptoms include the transmission being stuck in one gear, difficulty shifting, the Check Engine Light turning on, and reduced vehicle performance.

3. What causes the P18B5 code to appear on a 2016 Chevrolet Silverado?

The code can be triggered by damaged wiring, a faulty internal mode switch, a short circuit in the switch circuit, or internal transmission issues.

4. Can I drive my 2016 Chevrolet Silverado with the P18B5 code?

Itâ€™s not recommended to drive with this code active, as it may lead to further transmission damage or unsafe driving conditions due to shifting issues.

5. How do I diagnose the P18B5 code on my 2016 Chevrolet Silverado?

Start by inspecting the wiring and connectors for damage or corrosion, then test the internal mode switch with a multimeter to check for continuity or a short circuit.

6. How do I fix the P18B5 code on a 2016 Chevrolet Silverado?

Repairs may include replacing damaged wiring, repairing connectors, or replacing the internal mode switch if itâ€™s faulty.

7. How much does it cost to repair the P18B5 code on a 2016 Chevrolet Silverado?

Repair costs vary but typically range from $150 to $500, depending on whether the issue is a wiring repair or a full internal mode switch replacement.

8. What is the internal mode switch in a 2016 Chevrolet Silverado?

The internal mode switch is part of the transmission range sensor that helps the transmission control module identify the gear position selected.

9. Can a faulty internal mode switch cause other transmission problems?

Yes, a faulty switch can lead to erratic shifting, transmission slippage, or failure to engage certain gears.

10. Do I need a professional mechanic to repair the P18B5 code on my 2016 Chevrolet Silverado?

While basic checks like inspecting wiring can be done by a DIYer, diagnosing and replacing the internal mode switch often requires specialized tools and expertise, so professional assistance is recommended.