AutoCodes – Chevrolet – U0074 2014 Chevrolet Silverado

U0074 2014 Chevrolet Silverado Code - Control Module Communication Powertrain Expansion CAN Bus Off Malfunction

Quick Answer

The devices connected to the chassis high-speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Diagnosis of this Diagnostic Trouble Code (DTC) is accomplished via the vehicle symptom(s), Check for more codes, Faulty Control Module. 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: U0074 2014 Chevrolet Silverado indicates Control Module Communication Powertrain Expansion CAN Bus Off Malfunction.
Common causes: Common causes include Diagnosis of this Diagnostic Trouble Code (DTC) is accomplished via the vehicle symptom(s), Check for more codes, Faulty Control Module.
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 768

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 Apr 14, 2023

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code U0074 2014 Chevrolet Silverado Description

The devices connected to the chassis 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 when the ignition switch is in any position other than OFF. The chassis high-speed GMLAN serial data bus uses terminating resistors that are in parallel with the chassis high-speed GMLAN (+) and (-) circuits. The Diagnostic Trouble Code (DTC) will be set when a supervised periodic message that includes the transmitter device availability has not been received for more than 450 ms.

OBDII Code U0074 2014 Chevrolet Silverado - Control Module Communication Powertrain Expansion CAN Bus Off Malfunction - AutoCodes.com — U0074 2014 Chevrolet Silverado Code - Control Module Communication Powertrain Expansion CAN Bus Off Malfunction

What does this mean?

What are the Possible Causes of the DTC U0074 2014 Chevrolet Silverado?

Diagnosis of this Diagnostic Trouble Code (DTC) is accomplished via the vehicle symptom(s)
Check for more codes
Faulty Control Module
Control Module harness is open or shorted
Control Module circuit poor electrical connection

How to Fix the DTC U0074 2014 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 U0074 2014 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 U0074 2014 Chevrolet Silverado code?

Need more information on how to fix the U0074 2014 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 U0074 2014 Chevrolet Silverado Code

1. What does the OBDII code U0074 mean for a 2014 Chevrolet Silverado?

U0074 indicates a "Control Module Communication Powertrain Expansion CAN Bus Off Malfunction," meaning there's a problem with communication over the Controller Area Network (CAN) bus.

2. What are the common symptoms of the U0074 code on a 2014 Silverado?

Symptoms may include a check engine light, loss of communication with certain modules, erratic or non-functional gauges, and potential drivetrain performance issues.

3. What causes the U0074 code in a Chevy Silverado?

Common causes include wiring issues such as damaged or corroded CAN bus wiring, faulty control modules, a weak battery, or poor electrical connections.

4. Can a weak battery cause the U0074 code?

Yes, a weak or failing battery can lead to insufficient power for module communication, potentially triggering the U0074 code.

5. How do you diagnose the U0074 code on a 2014 Silverado?

Diagnosis involves using a scan tool to check for other related codes, inspecting the CAN bus wiring for damage, ensuring proper electrical connections, and testing the battery and alternator.

6. Can a faulty control module trigger the U0074 code?

Yes, a malfunctioning control module can disrupt CAN bus communication and cause the U0074 code to appear.

7. How do you fix the U0074 code on a 2014 Chevrolet Silverado?

Fixes may include repairing or replacing damaged wiring, cleaning corroded connections, replacing a faulty module, or ensuring the battery and alternator are functioning properly.

8. Is the U0074 code serious, and can I drive with it?

The severity depends on the affected module. While driving may be possible, ignoring the issue could lead to further communication or performance problems.

9. Does clearing the U0074 code with a scan tool fix the problem?

Clearing the code may reset the warning temporarily, but the underlying issue must be resolved to prevent the code from returning.

10. Can a software update fix the U0074 code in a 2014 Silverado?

In some cases, a software update for the affected module may resolve communication issues, but this should be done after verifying no hardware or wiring problems exist.