Engine-Codes.com
Engine-Codes – GMC – U1818 2017 GMC Sierra

U1818 2017 GMC Sierra Code - Lost Communication with Engine Control Module on Powertrain Expansion Communication Bus

Quick Answer

The U1818 diagnostic trouble code (DTC) for a 2017 GMC Sierra indicates that there has been a loss of communication with the Engine Control Module (ECM) on the Powertrain Expansion Communication Bus. Common causes include Faulty Engine Control Module (ECM), Damaged wiring or connectors in the communication bus, Malfunctioning module on the Powertrain Expansion Communication Bus. 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
U1818 2017 GMC Sierra indicates Lost Communication with Engine Control Module on Powertrain Expansion Communication Bus.
Common causes
Common causes include Faulty Engine Control Module (ECM), Damaged wiring or connectors in the communication bus, Malfunctioning module on the Powertrain Expansion Communication Bus.
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 Sep 13, 2024
💬 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 U1818 2017 GMC Sierra Description

The U1818 diagnostic trouble code (DTC) for a 2017 GMC Sierra indicates that there has been a loss of communication with the Engine Control Module (ECM) on the Powertrain Expansion Communication Bus. The ECM is a crucial component of the vehicle's engine management system, responsible for controlling various engine functions such as fuel injection, ignition timing, and emissions. The Powertrain Expansion Communication Bus is the network that allows different modules within the vehicle to communicate with each other.

OBDII Code U1818 2017 GMC Sierra - Lost Communication with Engine Control Module on Powertrain Expansion Communication Bus
U1818 2017 GMC Sierra Code - Lost Communication with Engine Control Module on Powertrain Expansion Communication Bus

Common Causes of U1818 2017 GMC Sierra

  1. Faulty Engine Control Module (ECM)
  2. Damaged wiring or connectors in the communication bus
  3. Malfunctioning module on the Powertrain Expansion Communication Bus
  4. Software glitch in the ECM or other modules
  5. Corrosion or water damage in the electrical connections

Symptoms of U1818 2017 GMC Sierra

  1. Check Engine Light illuminated on the dashboard
  2. Reduced engine performance
  3. Rough idling or misfiring
  4. Stalling or difficulty starting the engine
  5. Loss of certain engine functions such as cruise control or traction control

How to Fix U1818 2017 GMC Sierra

  1. Perform a thorough inspection of the wiring and connectors in the communication bus to check for any damage or corrosion.
  2. Test the Engine Control Module (ECM) to determine if it is functioning correctly or needs to be replaced.
  3. Check for any software updates or glitches in the ECM and other modules that may be causing the communication issue.
  4. Replace any faulty modules on the Powertrain Expansion Communication Bus if necessary.
  5. Clear the DTC and perform a test drive to ensure that the communication between the ECM and other modules is restored.

Cost to Fix U1818 2017 GMC Sierra

The typical repair costs for addressing a U1818 code on a 2017 GMC Sierra can vary depending on the specific cause of the issue. In general, the cost of parts such as a new ECM or modules, as well as labor for diagnosis and repair, can range from $300 to $800 or more. It is essential to factor in the specific diagnosis time and labor rates at auto repair shops, which can vary based on location, vehicle make and model, and engine type. Rates typically range between $80 and $150 per hour, with higher rates in metropolitan areas or at dealerships and lower rates at independent shops. It is advisable to obtain quotes from local shops for a more accurate estimate.

Need more information about the U1818 2017 GMC Sierra code?

Need more information on how to fix the U1818 2017 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1818 2017 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 U1818 2017 GMC Sierra Code

1. What does the OBDII code U1818 mean on a 2017 GMC Sierra?

The U1818 code indicates a loss of communication with the Engine Control Module (ECM) on the Powertrain Expansion Communication Bus.

2. What are common symptoms of the U1818 code on a GMC Sierra?

Symptoms may include a check engine light, reduced engine performance, erratic shifting, or failure to start.

3. What causes the U1818 code to appear on a 2017 GMC Sierra?

Common causes include faulty wiring, loose or corroded connectors, a malfunctioning ECM, or issues with the Powertrain Expansion Communication Bus.

4. Can I drive my GMC Sierra with the U1818 code active?

Driving with the U1818 code may lead to reduced performance or potential safety issues. It’s best to address the problem as soon as possible.

5. How do I diagnose the U1818 code on a 2017 GMC Sierra?

Diagnosis typically involves inspecting the wiring and connectors, testing communication bus continuity, and checking the ECM for proper functionality using a scan tool.

6. Is the U1818 code specific to the GMC Sierra?

No, the U1818 code can occur in other GM vehicles, but the specific symptoms and causes may vary.

7. What tools are needed to troubleshoot the U1818 code?

A diagnostic scan tool capable of reading manufacturer-specific codes and a multimeter for testing electrical connections are essential.

8. Can a weak battery cause the U1818 code on a GMC Sierra?

Yes, a weak or failing battery can cause communication issues, including the U1818 code.

9. How much does it cost to fix the U1818 code on a 2017 GMC Sierra?

Repair costs vary depending on the cause, ranging from $50 for simple wiring repairs to over $1,000 if the ECM needs replacement.

10. What should I check first when troubleshooting the U1818 code?

Start by inspecting the wiring and connectors related to the Powertrain Expansion Communication Bus and the ECM for damage or corrosion.

Discuss the causes and fixes for U1818 2017 GMC Sierra OBDII Code

Submit a New Comment

Code U1818 2017 GMC Sierra comments

No comments found for this page.