AutoCodes – Chevrolet – U1818 2018 Chevrolet Silverado

U1818 2018 Chevrolet Silverado Code - Lost Communication with Engine Control Module on Powertrain Expansion Communication Bus

Quick Answer

Devices connected to the powertrain high-speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Engine Control Module (ECM), Engine Control Module harness is open or shorted, Engine Control Module 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: U1818 2018 Chevrolet Silverado indicates Lost Communication with Engine Control Module on Powertrain Expansion Communication Bus.
Common causes: Common causes include Faulty Engine Control Module (ECM), Engine Control Module harness is open or shorted, Engine Control Module 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 243

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Jul 24, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1818 2018 Chevrolet Silverado Description

Devices connected to the powertrain high-speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the devices. The devices have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver device as an availability indication of the transmitter device. Each message contains the identification number of the transmitter device.
The Diagnostic Trouble Code (DTC) will be set when a supervised periodic message that includes the transmitter device availability has not been received.

OBDII Code U1818 2018 Chevrolet Silverado - Lost Communication with Engine Control Module on Powertrain Expansion Communication Bus - AutoCodes.com — U1818 2018 Chevrolet Silverado Code - Lost Communication with Engine Control Module on Powertrain Expansion Communication Bus

What does this mean?

What are the Possible Causes of the DTC U1818 2018 Chevrolet Silverado?

Faulty Engine Control Module (ECM)
Engine Control Module harness is open or shorted
Engine Control Module circuit poor electrical connection

How to Fix the DTC U1818 2018 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 U1818 2018 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 U1818 2018 Chevrolet Silverado code?

Need more information on how to fix the U1818 2018 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1818 2018 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 U1818 2018 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code U1818 on a 2018 Chevrolet Silverado?

- Common symptoms include engine stalling, rough idling, loss of power, and issues with the transmission.

2. What does the OBDII code U1818 indicate on a 2018 Chevrolet Silverado?

- The code U1818 indicates a communication problem between the Engine Control Module (ECM) and other modules on the Powertrain Expansion Communication Bus.

3. What are the possible causes of the U1818 code on a 2018 Chevrolet Silverado?

- Possible causes include faulty wiring or connectors, a malfunctioning Engine Control Module (ECM), a defective Powertrain Control Module (PCM), or issues with the communication bus.

4. How can I diagnose the U1818 code on my 2018 Chevrolet Silverado?

- Diagnosing the U1818 code may involve checking the wiring and connectors for any damage, testing the communication bus for faults, and using a scan tool to communicate with the ECM and other modules.

5. Can I drive my 2018 Chevrolet Silverado with the U1818 code present?

- It is not recommended to drive the vehicle with the U1818 code present, as it can lead to potential safety hazards and further damage to the vehicle.

6. How can I repair the U1818 code on my 2018 Chevrolet Silverado?

- Repairing the U1818 code may involve repairing or replacing damaged wiring and connectors, resetting the ECM, reprogramming modules, or replacing faulty components.

7. Will resetting the ECM clear the U1818 code on a 2018 Chevrolet Silverado?

- Resetting the ECM may temporarily clear the code, but if the underlying issue is not addressed, the code is likely to reappear.

8. How much does it cost to repair the U1818 code on a 2018 Chevrolet Silverado?

- Repair costs for the U1818 code can vary depending on the exact cause of the issue, but expect to pay anywhere from $100 to $500 for parts and labor.

9. Can a DIY enthusiast fix the U1818 code on a 2018 Chevrolet Silverado?

- While some DIY enthusiasts may be able to diagnose and repair the U1818 code, it is recommended to seek professional help due to the complexity of electrical systems in modern vehicles.

10. How long does it take to repair the U1818 code on a 2018 Chevrolet Silverado?

- The repair time for the U1818 code can vary based on the exact cause of the issue and the availability of parts, but it typically takes a few hours to a full day to complete the repair.