AutoCodes – Chevrolet – P18B7 2017 Chevrolet Silverado

P18B7 2017 Chevrolet Silverado Code - Internal Mode Switch 'C' 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: P18B7 2017 Chevrolet Silverado indicates Internal Mode Switch 'C' 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 421

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
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P18B7 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 C signal circuit voltage is between 0.966–1.68 V, for 1.75 s.

OBDII Code P18B7 2017 Chevrolet Silverado - Internal Mode Switch 'C' Circuit Shorted - AutoCodes.com — P18B7 2017 Chevrolet Silverado Code - Internal Mode Switch 'C' Circuit Shorted

What does this mean?

What are the Possible Causes of the DTC P18B7 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 P18B7 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 P18B7 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 P18B7 2017 Chevrolet Silverado code?

Need more information on how to fix the P18B7 2017 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P18B7 2017 Chevrolet Silverado code diagnosed by a professional: Find a repair shop in your area

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 P18B7 2017 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P18B7 on a 2017 Chevrolet Silverado?

- Common symptoms include issues with shifting gears, rough shifting, engine stalling, and the inability to start the vehicle.

2. What does the OBDII code P18B7 'Internal Mode Switch C Circuit Shorted' mean on a 2017 Chevrolet Silverado?

- This code indicates a short circuit in the Internal Mode Switch C circuit, which is responsible for communicating the gear position to the vehicle's computer.

3. What are the possible causes of the Internal Mode Switch 'C' Circuit Shorted code on a 2017 Chevrolet Silverado?

- Possible causes include a faulty internal mode switch, damaged wiring or connectors, a short circuit in the circuit, or issues with the transmission control module.

4. How can I diagnose and repair OBDII code P18B7 on my 2017 Chevrolet Silverado?

- To diagnose this code, you may need to inspect the internal mode switch, check the wiring and connectors for damage, and test the circuit for shorts. Repair may involve replacing the internal mode switch, repairing damaged wiring, or addressing any short circuits.

5. Can driving with the Internal Mode Switch 'C' Circuit Shorted code on a 2017 Chevrolet Silverado cause further damage?

- Continuing to drive with this code may lead to further transmission issues, such as improper shifting or transmission failure, so it's recommended to address the problem promptly.

6. How much does it typically cost to repair OBDII code P18B7 on a 2017 Chevrolet Silverado?

- The cost of repair can vary depending on the exact cause of the issue, but it may range from a few hundred to over a thousand dollars, including parts and labor.

7. Is it safe to continue driving my 2017 Chevrolet Silverado with the Internal Mode Switch 'C' Circuit Shorted code?

- It is not recommended to continue driving the vehicle with this code present, as it can lead to potential safety hazards and further damage to the transmission.

8. Can I reset the OBDII code P18B7 on my 2017 Chevrolet Silverado without making any repairs?

- While you can clear the code using an OBDII scanner, the underlying issue causing the code will still persist, and the code is likely to return until the problem is fixed.

9. Will fixing the Internal Mode Switch 'C' Circuit Shorted code improve the performance of my 2017 Chevrolet Silverado?

- Yes, addressing this code should help restore proper transmission function, improve shifting performance, and prevent further damage to the transmission system.

10. How long does it typically take to repair OBDII code P18B7 on a 2017 Chevrolet Silverado?

- The repair time can vary based on the exact cause of the issue and the complexity of the repair, but it may take a few hours to a full day to diagnose and fix the problem.