AutoCodes – Chevrolet – U18C8 2016 Chevrolet Silverado

U18C8 2016 Chevrolet Silverado Code - Glow Plug Control Module Lost Communication with Engine Control Module

Quick Answer

Devices connected to the 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: U18C8 2016 Chevrolet Silverado indicates Glow Plug Control Module Lost Communication with Engine Control Module.
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 328

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 U18C8 2016 Chevrolet Silverado Description

Devices connected to the 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 U18C8 2016 Chevrolet Silverado - Glow Plug Control Module Lost Communication with Engine Control Module - AutoCodes.com — U18C8 2016 Chevrolet Silverado Code - Glow Plug Control Module Lost Communication with Engine Control Module

What does this mean?

What are the Possible Causes of the DTC U18C8 2016 Chevrolet Silverado?

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

How to Fix the DTC U18C8 2016 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 U18C8 2016 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 U18C8 2016 Chevrolet Silverado code?

Need more information on how to fix the U18C8 2016 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 U18C8 2016 Chevrolet Silverado Code

1. What does the OBDII code U18C8 indicate on a 2016 Chevrolet Silverado?

The U18C8 code suggests that the glow plug control module is not communicating with the engine control module. This issue can lead to problems with engine starting and performance, especially in cold weather.

2. What are common symptoms of the U18C8 code in a 2016 Chevrolet Silverado?

Symptoms may include difficulty starting the engine, especially in cold conditions, a decrease in engine power, the Check Engine light turning on, and possibly the engine misfiring.

3. What could cause the U18C8 code to appear in a 2016 Chevrolet Silverado?

Potential causes include faulty wiring or connections between the glow plug control module and the engine control module, a defective glow plug control module, or a malfunctioning engine control module.

4. How can I diagnose the U18C8 code in my 2016 Chevrolet Silverado?

Diagnosis should begin with a visual inspection of the wiring and connections related to the glow plug control module. Use an OBDII scanner to check for additional codes that might indicate where the failure is occurring. Testing the glow plug control module and the engine control module may also be necessary.

5. What are the steps to fix the U18C8 code on a 2016 Chevrolet Silverado?

Repairing this code may involve repairing or replacing damaged wiring, securing loose connections, replacing the faulty glow plug control module, or in some cases, repairing or replacing the engine control module.

6. Is it safe to drive my 2016 Chevrolet Silverado with the U18C8 code active?

While you might be able to drive with this code active, it is advisable to address the issue promptly. Operating the vehicle with impaired glow plugs can lead to poor engine performance and increased difficulty in starting the engine, particularly in colder weather.

7. Can a U18C8 code affect the fuel efficiency of my 2016 Chevrolet Silverado?

Yes, this code can affect fuel efficiency. When the glow plugs are not functioning properly, the engine may not reach optimal operating temperature efficiently, leading to increased fuel consumption and reduced performance.

8. What tools are needed to diagnose the U18C8 code on a 2016 Chevrolet Silverado?

Diagnosing this code typically requires an OBDII scanner, a multimeter for testing electrical connections and voltages, and possibly a diagnostic scan tool specific to Chevrolet vehicles to run more detailed diagnostics.