AutoCodes – Chevrolet – P18B5 2017 Chevrolet Silverado

P18B5 2017 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 2017 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 465

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 2017 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 2017 Chevrolet Silverado - Internal Mode Switch 'A' Circuit Shorted - AutoCodes.com — P18B5 2017 Chevrolet Silverado Code - Internal Mode Switch 'A' Circuit Shorted

What does this mean?

What are the Possible Causes of the DTC P18B5 2017 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 2017 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 2017 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 2017 Chevrolet Silverado code?

Need more information on how to fix the P18B5 2017 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 2017 Chevrolet Silverado Code

1. What does the OBDII code P18B5 for a 2017 Chevrolet Silverado indicate?

The code P18B5 on a 2017 Chevrolet Silverado points to an issue with the Internal Mode Switch 'A' Circuit being shorted.

2. What are the common symptoms of the Internal Mode Switch 'A' Circuit Shorted code on a 2017 Chevrolet Silverado?

Common symptoms of this issue may include erratic shifting behavior, incorrect gear selection display on the dashboard, and potential transmission-related problems.

3. What can cause the Internal Mode Switch 'A' Circuit to short on a 2017 Chevrolet Silverado?

Possible causes of this problem can include a faulty internal mode switch, damaged wiring or connectors, water intrusion, or corrosion in the circuit.

4. How do you diagnose the Internal Mode Switch 'A' Circuit Shorted code on a 2017 Chevrolet Silverado?

Diagnosing this code typically involves performing a thorough inspection of the internal mode switch, checking the wiring and connectors for damage, and using a scan tool to gather data on the transmission system.

5. Can driving the 2017 Chevrolet Silverado with the P18B5 code cause further damage?

Continuing to drive the vehicle with the Internal Mode Switch 'A' Circuit Shorted code may lead to transmission issues and potential damage if left unresolved.

6. How can the Internal Mode Switch 'A' Circuit Shorted code on a 2017 Chevrolet Silverado be repaired?

Repairing this issue often involves replacing the faulty internal mode switch, repairing any damaged wiring or connectors, and clearing the trouble codes with a scan tool.

7. Is it safe to continue driving a 2017 Chevrolet Silverado with the P18B5 code illuminated?

It is not recommended to drive the vehicle with the P18B5 code present, as it can lead to further transmission problems and potential safety hazards.

8. Can a DIY enthusiast fix the Internal Mode Switch 'A' Circuit Shorted issue on a 2017 Chevrolet Silverado?

While some DIY enthusiasts may have the skills to address this problem, it is advisable to consult a professional mechanic for an accurate diagnosis and proper repair.

9. How much does it typically cost to repair the P18B5 code on a 2017 Chevrolet Silverado?

The cost of repairing the Internal Mode Switch 'A' Circuit Shorted issue can vary depending on the extent of the damage, but it may range from a few hundred to a thousand dollars at a repair shop.

10. Are there any preventive measures to avoid the Internal Mode Switch 'A' Circuit Shorted code on a 2017 Chevrolet Silverado?

Regular maintenance checks, ensuring proper wiring connections, and addressing any transmission issues promptly can help prevent the occurrence of the P18B5 trouble code.