AutoCodes – Chevrolet – U18A2 2015 Chevrolet Silverado

U18A2 2015 Chevrolet Silverado Code - Lost Communication with Fuel Pump Driver Control Module

Quick Answer

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Fuel Pump Driver Control Module, Fuel Pump Driver Control Module harness is open or shorted, Fuel Pump Driver 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: U18A2 2015 Chevrolet Silverado indicates Lost Communication with Fuel Pump Driver Control Module.
Common causes: Common causes include Faulty Fuel Pump Driver Control Module, Fuel Pump Driver Control Module harness is open or shorted, Fuel Pump Driver 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 580

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 Apr 14, 2023

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code U18A2 2015 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 set a supervised periodic message that includes the transmitter device availability that has not been received.

OBDII Code U18A2 2015 Chevrolet Silverado - Lost Communication with Fuel Pump Driver Control Module - AutoCodes.com — U18A2 2015 Chevrolet Silverado Code - Lost Communication with Fuel Pump Driver Control Module

What does this mean?

What are the Possible Causes of the DTC U18A2 2015 Chevrolet Silverado?

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

How to Fix the DTC U18A2 2015 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 does this mean?

Code Tech Notes

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.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U18A2 2015 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 U18A2 2015 Chevrolet Silverado code?

Need more information on how to fix the U18A2 2015 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 U18A2 2015 Chevrolet Silverado Code

1. What are the common symptoms of OBDII code U18A2 in a 2015 Chevrolet Silverado?

The common symptoms include the check engine light illuminating, difficulty starting the vehicle, stalling while driving, and issues with fuel delivery.

2. What can cause the OBDII code U18A2 in a 2015 Chevrolet Silverado?

The code U18A2 typically indicates a communication problem between the vehicle's onboard computer and the Fuel Pump Driver Control Module. This can be caused by wiring issues, a faulty module, or a problem with the ECM.

3. How can I diagnose the issue related to code U18A2 in my 2015 Chevrolet Silverado?

Diagnosing the problem usually involves checking the wiring connections between the ECM and the Fuel Pump Driver Control Module, testing the module for functionality, and using a diagnostic scanner to read any stored fault codes.

4. What are some repair tips for fixing the U18A2 code in a 2015 Chevrolet Silverado?

Repair tips may include checking and repairing any damaged wiring, replacing the Fuel Pump Driver Control Module if necessary, and ensuring proper communication between the module and the ECM.

5. Can I drive my 2015 Chevrolet Silverado with the U18A2 code present?

It is not recommended to drive the vehicle with the U18A2 code present, as it can lead to potential fuel delivery issues that may cause the vehicle to stall unexpectedly.

6. How much does it typically cost to repair the U18A2 code in a 2015 Chevrolet Silverado?

The cost of repairing the U18A2 code can vary depending on the exact cause of the issue. It may involve simple wiring repairs or require replacing the Fuel Pump Driver Control Module, which can range from a few hundred to over a thousand dollars.

7. Can I reset the U18A2 code in my 2015 Chevrolet Silverado on my own?

While you can clear the code with an OBDII scanner, it is important to diagnose and address the underlying issue causing the code to prevent it from reoccurring.

8. Is the U18A2 code in a 2015 Chevrolet Silverado a common problem?

The U18A2 code specifically related to lost communication with the Fuel Pump Driver Control Module may not be as common as other codes, but it can still occur due to various factors like wiring issues or module failure.

9. Can a DIY enthusiast fix the U18A2 code issue in a 2015 Chevrolet Silverado?

Depending on the DIYer's skill level and access to tools, some may be able to address simpler causes like wiring issues. However, more complex problems like module replacement may require professional expertise.

10. How long does it take to repair the U18A2 code issue in a 2015 Chevrolet Silverado?

The repair time can vary based on the exact cause of the issue and the expertise of the technician. Simple fixes like wiring repairs may take a couple of hours, while module replacement could extend the repair time.