AutoCodes – Chevrolet – P18BB 2015 Chevrolet Silverado

P18BB 2015 Chevrolet Silverado Code - Internal Mode Switch 'B' Circuit Stuck Off 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: P18BB 2015 Chevrolet Silverado indicates Internal Mode Switch 'B' Circuit Stuck Off 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 189

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 P18BB 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 B signal circuit has an invalid voltage range of 1.68 – 2.38 V for 2.7 s.

OBDII Code P18BB 2015 Chevrolet Silverado - Internal Mode Switch 'B' Circuit Stuck Off Invalid Voltage Range - AutoCodes.com — P18BB 2015 Chevrolet Silverado Code - Internal Mode Switch 'B' Circuit Stuck Off Invalid Voltage Range

What does this mean?

What are the Possible Causes of the DTC P18BB 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 P18BB 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 P18BB 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 P18BB 2015 Chevrolet Silverado code?

Need more information on how to fix the P18BB 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 P18BB 2015 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code P18BB in a 2015 Chevrolet Silverado?

- Common symptoms include issues with shifting gears, erratic transmission behavior, and illuminated warning lights on the dashboard.

2. What does the OBDII code P18BB 'Internal Mode Switch B Circuit Stuck Off Invalid Voltage Range' mean in a 2015 Chevrolet Silverado?

- This code indicates a problem with the internal mode switch B circuit in the transmission, specifically related to an invalid voltage range being detected.

3. What are some possible causes of the Internal Mode Switch 'B' Circuit Stuck Off Invalid Voltage Range code in a 2015 Chevrolet Silverado?

- Potential causes include a faulty internal mode switch, damaged wiring or connectors, low transmission fluid levels, or issues with the transmission control module.

4. How can I diagnose the Internal Mode Switch 'B' Circuit Stuck Off Invalid Voltage Range issue in my 2015 Chevrolet Silverado?

- Diagnosis typically involves using a diagnostic scanner to retrieve the trouble codes, conducting a visual inspection of wiring and connectors, and testing the internal mode switch for proper operation.

5. Can driving with the OBDII code P18BB present in a 2015 Chevrolet Silverado cause further damage?

- Continuing to drive with this code can potentially lead to further transmission issues and may result in more severe damage over time if not addressed promptly.

6. What are some repair tips for fixing the Internal Mode Switch 'B' Circuit Stuck Off Invalid Voltage Range code in a 2015 Chevrolet Silverado?

- Repair tips may include replacing the internal mode switch, repairing or replacing damaged wiring, ensuring proper transmission fluid levels, and reprogramming the transmission control module if necessary.

7. Is it possible to reset the OBDII code P18BB in a 2015 Chevrolet Silverado without fixing the underlying issue?

- While you can clear the code with a diagnostic scanner, it is important to address the root cause of the problem to prevent it from recurring and potentially causing further damage.

8. How much does it typically cost to repair the Internal Mode Switch 'B' Circuit Stuck Off Invalid Voltage Range issue in a 2015 Chevrolet Silverado?

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

9. Can I fix the OBDII code P18BB issue in my 2015 Chevrolet Silverado myself, or should I take it to a professional mechanic?

- While some DIY enthusiasts may be able to address this issue themselves, it is recommended to consult a professional mechanic with experience in transmission repairs for proper diagnosis and repair.

10. How can I prevent the Internal Mode Switch 'B' Circuit Stuck Off Invalid Voltage Range code from recurring in my 2015 Chevrolet Silverado?

- Regularly maintaining your vehicle, checking transmission fluid levels, addressing any warning lights promptly, and ensuring proper operation of transmission components can help prevent this code from reoccurring.