Engine-CodesChevrolet – U18A2 2018 Chevrolet Silverado

U18A2 2018 Chevrolet Silverado Code - Lost Communication with Fuel Pump Driver Control Module

Quick Answer

The U18A2 diagnostic trouble code (DTC) for a 2018 Chevrolet Silverado indicates that there has been a loss of communication with the Fuel Pump Driver Control Module. Common causes include Faulty wiring or connections, Malfunctioning Fuel Pump Driver Control Module, Issues with the electronic control unit (ECU). 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
U18A2 2018 Chevrolet Silverado indicates Lost Communication with Fuel Pump Driver Control Module.
Common causes
Common causes include Faulty wiring or connections, Malfunctioning Fuel Pump Driver Control Module, Issues with the electronic control unit (ECU).
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.
Table of contents Created and updated by William Orellana on Sep 13, 2024
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Code U18A2 2018 Chevrolet Silverado Description

The U18A2 diagnostic trouble code (DTC) for a 2018 Chevrolet Silverado indicates that there has been a loss of communication with the Fuel Pump Driver Control Module. This module is responsible for controlling the fuel pump's operation, ensuring that the correct amount of fuel is delivered to the engine at all times. When communication with this module is lost, it can lead to a variety of issues that affect the vehicle's performance and drivability.

OBDII Code U18A2 2018 Chevrolet Silverado - Lost Communication with Fuel Pump Driver Control Module
U18A2 2018 Chevrolet Silverado Code - Lost Communication with Fuel Pump Driver Control Module

Common Causes of U18A2 2018 Chevrolet Silverado

  1. Faulty wiring or connections
  2. Malfunctioning Fuel Pump Driver Control Module
  3. Issues with the electronic control unit (ECU)
  4. Corrosion or damage to electrical components
  5. Software issues affecting communication protocols

Symptoms of U18A2 2018 Chevrolet Silverado

  1. Engine misfires or runs poorly
  2. Stalling or difficulty starting
  3. Reduced fuel efficiency
  4. Vehicle going into "limp mode"
  5. Check engine light illuminated

How to Fix U18A2 2018 Chevrolet Silverado

  1. Begin by conducting a thorough inspection of the wiring and connections between the Fuel Pump Driver Control Module and the ECU. Repair or replace any damaged wiring or connectors.
  2. Test the Fuel Pump Driver Control Module to determine if it is functioning correctly. Replace the module if necessary.
  3. Check the ECU for any faults or software issues that may be affecting communication with the fuel pump module. Address any issues found.
  4. Clear the DTC from the vehicle's memory using a diagnostic scanner.
  5. Test drive the vehicle to ensure that the issue has been resolved and that communication with the fuel pump module has been restored.

Cost to Fix U18A2 2018 Chevrolet Silverado

The typical repair costs for addressing a U18A2 DTC can vary depending on the specific cause of the issue. In general, the cost of parts such as a new Fuel Pump Driver Control Module can range from $200 to $500, while labor costs can range from $100 to $300. Overall, the total repair cost for this issue could range from $300 to $800. It is important to note that these are rough estimates, and actual costs may vary based on factors such as location, vehicle make and model, and labor rates at the repair shop. It is advisable to consult with a qualified mechanic for a more accurate cost estimate.

Tech Notes for U18A2 2018 Chevrolet Silverado

There is a Factory Service Bulletin for the following Chevrolet Models:



- 2014-2018 Chevrolet Silverado

- 2015-2018 Chevrolet Suburban

- 2015-2018 Chevrolet Tahoe



If the Diagnostic Trouble Codes (DTC) P2635, U0074, and/or U18A2 are set, it may be found that the actual fuel pressure (low-pressure system) will be reading substantially higher than desired fuel pressure, in this case, the cause of the problem is a loss of communication between Engine Control Module (ECM) and Fuel Pump Control Module (FPCM).



- Diagnose for any communication DTCs set (U0074 would take priority over U18A2 if both set) before addressing DTC P2635.

- If DTC P2635 is not resolved by correcting the communication DTCs, only then should diagnose the DTC P2635.

- It has been found that a communication issue between the FPCM and ECM can potentially induce DTC P2635 and result in a pressure differential between actual and desired fuel system pressures.

- If the actual fuel pressure is substantially higher than desired (10 psi / 70 kPa or more), replacement of the fuel pump control module or fuel system components typically will not resolve this issue.

- If the actual fuel pressure is substantially lower than desired (10 psi / 70 kPa or more), this Factory Service Bulletin would NOT apply. It would be recommended to diagnose low actual fuel pressure.

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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 U18A2 2018 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code U18A2 in a 2018 Chevrolet Silverado related to lost communication with the Fuel Pump Driver Control Module?

- Common symptoms include issues with starting the vehicle, loss of power during operation, and potential stalling.

2. What are some possible causes of the U18A2 code indicating lost communication with the Fuel Pump Driver Control Module in a 2018 Chevrolet Silverado?

- Potential causes may include a faulty Fuel Pump Driver Control Module, damaged wiring or connectors, software glitches, or a malfunctioning powertrain control module (PCM).

3. How can I diagnose the U18A2 trouble code in my 2018 Chevrolet Silverado related to communication issues with the Fuel Pump Driver Control Module?

- Diagnosing the code typically involves using a diagnostic scanner to retrieve the specific trouble codes, checking the wiring for any visible damage, and testing the Fuel Pump Driver Control Module for functionality.

4. What are some tips for repairing the U18A2 code indicating lost communication with the Fuel Pump Driver Control Module in a 2018 Chevrolet Silverado?

- Repair tips may include repairing or replacing damaged wiring, ensuring connectors are securely attached, updating software if necessary, and replacing the Fuel Pump Driver Control Module if it is faulty.

5. Can a DIY enthusiast fix the U18A2 code related to lost communication with the Fuel Pump Driver Control Module in a 2018 Chevrolet Silverado?

- While some basic troubleshooting steps can be done by a DIY enthusiast, diagnosing and repairing communication issues with the Fuel Pump Driver Control Module may require advanced tools and expertise, so it's recommended to consult a professional mechanic.

6. Is it safe to continue driving my 2018 Chevrolet Silverado with the U18A2 trouble code indicating communication problems with the Fuel Pump Driver Control Module?

- It is not advisable to continue driving the vehicle with unresolved communication issues related to the Fuel Pump Driver Control Module, as it can lead to potential safety hazards and further damage to the vehicle.

7. How much does it typically cost to repair the U18A2 code signifying lost communication with the Fuel Pump Driver Control Module in a 2018 Chevrolet Silverado?

- The cost of repairs can vary depending on the specific issue causing the code, but it may range from a few hundred to over a thousand dollars, including parts and labor.

8. Are there any recalls or technical service bulletins (TSBs) related to the U18A2 code in a 2018 Chevrolet Silverado for lost communication with the Fuel Pump Driver Control Module?

- It is recommended to check with authorized Chevrolet dealerships or online resources for any recalls or TSBs related to the U18A2 code in the 2018 Chevrolet Silverado to see if there are known issues or solutions provided by the manufacturer.

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