Engine-Codes.com
Engine-Codes – GMC – P189A 2014 GMC Sierra

P189A 2014 GMC Sierra Code - Four Wheel Drive Range Secondary Signal Message Counter Incorrect

Quick Answer

The P189A code is specific to GMC vehicles and indicates a malfunction related to the four-wheel-drive (4WD) system, specifically concerning the secondary signal message counter. Common causes include Faulty transfer case control module or software issues, Damaged or corroded wiring and connectors related to the 4WD system, Malfunctioning sensors that monitor the 4WD operation. 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
P189A 2014 GMC Sierra indicates Four Wheel Drive Range Secondary Signal Message Counter Incorrect.
Common causes
Common causes include Faulty transfer case control module or software issues, Damaged or corroded wiring and connectors related to the 4WD system, Malfunctioning sensors that monitor the 4WD operation.
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.
What is this?
Table of contents Created and updated by William Orellana on Jun 18, 2025
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P189A 2014 GMC Sierra Description

The P189A code is specific to GMC vehicles and indicates a malfunction related to the four-wheel-drive (4WD) system, specifically concerning the secondary signal message counter. This code suggests that the vehicle's onboard diagnostic system has detected an inconsistency in the communication between the transfer case control module and other related systems, such as the transmission control module or the engine control module.
OBDII Code P189A 2014 GMC Sierra - Four Wheel Drive Range Secondary Signal Message Counter Incorrect
P189A 2014 GMC Sierra Code - Four Wheel Drive Range Secondary Signal Message Counter Incorrect

Common Causes of P189A 2014 GMC Sierra

  1. Faulty transfer case control module or software issues.
  2. Damaged or corroded wiring and connectors related to the 4WD system.
  3. Malfunctioning sensors that monitor the 4WD operation.
  4. Low transmission fluid levels or fluid contamination affecting system performance.
  5. Mechanical issues within the transfer case itself, such as worn gears or bearings.

Symptoms of P189A 2014 GMC Sierra

  1. Difficulty engaging or disengaging 4WD modes.
  2. Erratic shifting or slipping in the drivetrain.
  3. Warning lights illuminated on the dashboard, particularly related to the 4WD system.
  4. Unusual noises from the transfer case or drivetrain when attempting to switch modes.
  5. Reduced traction or handling performance in slippery conditions.

How to Fix P189A 2014 GMC Sierra

  1. Diagnostic Scan: Begin with a thorough diagnostic scan to confirm the P189A code and check for any additional codes that may provide further insight into the issue.
  2. Visual Inspection: Conduct a visual inspection of the wiring and connectors associated with the transfer case control module and the 4WD system to identify any signs of damage or corrosion.
  3. Sensor Testing: Test the functionality of the relevant sensors, including the transfer case position sensor, to ensure they are operating within specifications.
  4. Module Reprogramming: If the control module is determined to be faulty or has outdated software, reprogramming or replacing the module may be necessary.
  5. Fluid Check and Replacement: Inspect the transmission fluid levels and condition; replace any contaminated fluid and ensure that levels are adequate for optimal operation.

Cost to Fix P189A 2014 GMC Sierra

The typical repair costs for addressing a P189A code can vary widely based on the specific diagnosis and repairs needed. On average, you might expect to spend between $150 to $600, which includes parts and labor. Diagnostic time may take 1 to 2 hours, and labor rates at auto repair shops can range from $80 to $150 per hour. Rates may be higher at dealerships or in metropolitan areas, while independent shops may offer lower rates. It is advisable to check local rates and obtain estimates from multiple shops for a more precise cost assessment.

Need more information about the P189A 2014 GMC Sierra code?

Need more information on how to fix the P189A 2014 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P189A 2014 GMC Sierra 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 P189A 2014 GMC Sierra Code

No Frequently Asked Questions about P189A 2014 GMC Sierra Code found.

Discuss the causes and fixes for P189A 2014 GMC Sierra OBDII Code

Submit a New Comment

Code P189A 2014 GMC Sierra comments

No comments found for this page.