AutoCodes – GMC – P182B GMC

P182B GMC Code - Internal Mode Switch 'B' Circuit Low Voltage

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: P182B GMC indicates Internal Mode Switch 'B' Circuit Low Voltage.
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 3,276

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 P182B GMC 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 voltage is less than 0.7 V, for 1.75 s.

OBDII Code P182B GMC - Internal Mode Switch 'B' Circuit Low Voltage - AutoCodes.com — P182B GMC Code - Internal Mode Switch 'B' Circuit Low Voltage

What does this mean?

What are the Possible Causes of the DTC P182B GMC?

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 P182B GMC?

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 P182B GMC 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 P182B GMC code?

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Information for Specific GMC Models

P182B 2014 GMC Sierra — Internal Mode Switch 'B' Circuit Low Voltage
P182B 2015 GMC Sierra — Internal Mode Switch 'B' Circuit Low Voltage
P182B 2016 GMC Sierra — Internal Mode Switch 'B' Circuit Low Voltage
P182B 2017 GMC Sierra — Internal Mode Switch 'B' Circuit Low Voltage
P182B 2018 GMC Sierra — Internal Mode Switch 'B' Circuit Low Voltage

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 P182B GMC Code

1. What does the OBDII code P182B mean on a GMC vehicle?

P182B indicates that the Internal Mode Switch (IMS) 'B' circuit is experiencing low voltage, which suggests a potential problem with the switch, wiring, or related components in the transmission system.

2. What are the common symptoms of code P182B on a GMC?

Symptoms may include difficulty shifting gears, the transmission stuck in a single gear, the check engine light illuminated, or reduced overall performance in the transmission system.

3. What causes the P182B code to appear?

Common causes include faulty wiring or connections in the IMS circuit, a defective Internal Mode Switch, a failing transmission control module (TCM), or low transmission fluid levels.

4. How can I diagnose the P182B code on my GMC?

Start by inspecting the IMS wiring and connectors for damage or corrosion. Use a multimeter to check the voltage and continuity of the circuit, and scan for additional transmission-related codes for further clues.

5. Can low transmission fluid cause the P182B code?

Yes, low or contaminated transmission fluid can cause improper IMS operation, potentially triggering the P182B code.

6. Is it safe to drive with the P182B code active?

Driving with this code is not recommended as it may cause further damage to the transmission or result in unsafe driving conditions due to gear shifting issues.

7. How is the P182B code typically repaired?

Repairs may involve replacing the Internal Mode Switch, repairing or replacing damaged wiring, cleaning corroded connectors, refilling or flushing the transmission fluid, or reprogramming the TCM.

8. How much does it cost to fix the P182B code on a GMC?

The repair cost varies depending on the underlying issue, but replacing the IMS can cost between $200 and $400, while wiring repairs may cost less. Labor charges will also vary by location.

9. Can a faulty Transmission Control Module (TCM) cause the P182B code?

Yes, a malfunctioning TCM can cause improper voltage readings in the IMS circuit and trigger the P182B code, though this is less common than wiring or IMS issues.

10. What tools are needed to troubleshoot the P182B code?

You'll need an OBDII scanner, a multimeter for electrical testing, and potentially tools for removing and inspecting the IMS and its wiring.