AutoCodes – Chevrolet – P18B5 2015 Chevrolet Silverado

P18B5 2015 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 2015 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 264

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 2015 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 2015 Chevrolet Silverado - Internal Mode Switch 'A' Circuit Shorted - AutoCodes.com — P18B5 2015 Chevrolet Silverado Code - Internal Mode Switch 'A' Circuit Shorted

What does this mean?

What are the Possible Causes of the DTC P18B5 2015 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 2015 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 2015 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 2015 Chevrolet Silverado code?

Need more information on how to fix the P18B5 2015 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 2015 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P18B5 in a 2015 Chevrolet Silverado?

- Common symptoms include issues with gear shifting, rough idling, difficulty starting the vehicle, and the check engine light being illuminated.

2. What does the OBDII code P18B5 'Internal Mode Switch 'A' Circuit Shorted' mean in a 2015 Chevrolet Silverado?

- The code indicates a malfunction in the internal mode switch 'A' circuit, which can affect the transmission's operation.

3. What are the possible causes of OBDII code P18B5 in a 2015 Chevrolet Silverado?

- The code can be triggered by a faulty internal mode switch, damaged wiring or connectors, a short circuit in the circuit, or a malfunctioning transmission control module.

4. How can I diagnose the cause of OBDII code P18B5 in my 2015 Chevrolet Silverado?

- Diagnosis involves inspecting the internal mode switch, checking the wiring and connectors for damage, testing the circuit for shorts, and scanning the transmission control module for related faults.

5. Can I continue driving my 2015 Chevrolet Silverado with OBDII code P18B5 present?

- It is not recommended to drive the vehicle with this code present as it can lead to transmission issues and potentially cause further damage.

6. How serious is OBDII code P18B5 in a 2015 Chevrolet Silverado?

- The code should be addressed promptly as it can affect the transmission's performance and reliability, leading to potential safety hazards and costly repairs if not fixed in a timely manner.

7. Is it possible to reset the OBDII code P18B5 in a 2015 Chevrolet Silverado without fixing the underlying issue?

- While you can clear the code temporarily, it is crucial to address the root cause to prevent the issue from recurring and causing further damage.

8. Can a DIY enthusiast repair OBDII code P18B5 in a 2015 Chevrolet Silverado?

- Depending on your skill level and access to tools, you may be able to address simpler causes like loose connections or damaged wiring. However, more complex issues may require professional diagnosis and repair.

9. How much does it typically cost to repair OBDII code P18B5 in a 2015 Chevrolet Silverado?

- Repair costs can vary depending on the exact cause of the issue, but they may range from a few hundred to a thousand dollars, including parts and labor.

10. Are there any preventive measures to avoid OBDII code P18B5 in a 2015 Chevrolet Silverado?

- Regular maintenance, checking for loose connections, and addressing any transmission-related issues promptly can help prevent the occurrence of this code in your vehicle.