AutoCodes – GMC – U18A5 GMC

U18A5 GMC Code - Lost Communication With Fuel Injector Control Module On Powertrain Expansion CAN Bus

Quick Answer

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Fuel Injector Control Module, Fuel Injector Control Module harness is open or shorted, Fuel Injector 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: U18A5 GMC indicates Lost Communication With Fuel Injector Control Module On Powertrain Expansion CAN Bus.
Common causes: Common causes include Faulty Fuel Injector Control Module, Fuel Injector Control Module harness is open or shorted, Fuel Injector 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 447

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 Jun 08, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U18A5 GMC 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 set a supervised periodic message that includes the transmitter device availability that has not been received.

OBDII Code U18A5 GMC - Lost Communication With Fuel Injector Control Module On Powertrain Expansion CAN Bus - AutoCodes.com — U18A5 GMC Code - Lost Communication With Fuel Injector Control Module On Powertrain Expansion CAN Bus

What does this mean?

What are the Possible Causes of the DTC U18A5 GMC?

Faulty Fuel Injector Control Module
Fuel Injector Control Module harness is open or shorted
Fuel Injector Control Module circuit poor electrical connection

How to Fix the DTC U18A5 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 U18A5 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 U18A5 GMC code?

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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 U18A5 GMC Code

1. What are the common symptoms of OBDII code U18A5 GMC?

- Common symptoms include engine misfires, rough idling, poor fuel efficiency, and the illumination of the Check Engine Light.

2. What can cause the U18A5 GMC code to appear?

- The code may appear due to faulty wiring or connectors, a malfunctioning Fuel Injector Control Module, issues with the Powertrain Expansion CAN Bus, or a communication breakdown between components.

3. How can I diagnose the U18A5 GMC code?

- Diagnosis typically involves using an OBDII scanner to retrieve the code, checking for any additional related codes, inspecting the wiring and connectors for damage, and testing the Fuel Injector Control Module and CAN bus for proper functionality.

4. Is it safe to drive with the U18A5 GMC code present?

- It is generally not recommended to drive with this code present, as it can lead to potential engine performance issues and further damage if left unaddressed.

5. What are some repair tips for fixing the U18A5 GMC code?

- Repair tips include checking and repairing any damaged wiring or connectors, replacing the Fuel Injector Control Module if necessary, ensuring proper communication between components, and clearing the code to see if it returns.

6. Can I reset the U18A5 GMC code on my own?

- Yes, you can reset the code using an OBDII scanner or by disconnecting the vehicle's battery for a few minutes. However, it is important to address the underlying issue causing the code to prevent it from reoccurring.

7. How much does it cost to repair the U18A5 GMC code?

- The cost of repair can vary depending on the specific cause of the code and the labor rates in your area. It is recommended to consult with a qualified mechanic for an accurate estimate.

8. Will the U18A5 GMC code affect my vehicle's performance?

- Yes, the code can affect your vehicle's performance by causing engine misfires, rough idling, and decreased fuel efficiency. It is important to address the issue promptly to prevent further damage.

9. Can a DIY enthusiast fix the U18A5 GMC code at home?

- While some DIY enthusiasts may be able to address the code by checking and repairing wiring or connectors, diagnosing and repairing issues related to the Fuel Injector Control Module or CAN bus may require professional expertise.

10. How long does it typically take to repair the U18A5 GMC code?

- The repair time can vary depending on the complexity of the issue causing the code. Simple fixes like repairing wiring may take a short time, while more involved repairs could require several hours or more.