AutoCodes – Chevrolet – U1878 Chevrolet

U1878 Chevrolet Code - Drive Motor B Control Module Lost Communication With Battery Energy Control Module

Quick Answer

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Battery Energy Control Module, Battery Energy Control Module harness is open or shorted, Battery Energy 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: U1878 Chevrolet indicates Drive Motor B Control Module Lost Communication With Battery Energy Control Module.
Common causes: Common causes include Faulty Battery Energy Control Module, Battery Energy Control Module harness is open or shorted, Battery Energy 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 675

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 U1878 Chevrolet 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 if a supervised periodic message that includes the transmitter device availability has not been received.

OBDII Code U1878 Chevrolet - Drive Motor B Control Module Lost Communication With Battery Energy Control Module - AutoCodes.com — U1878 Chevrolet Code - Drive Motor B Control Module Lost Communication With Battery Energy Control Module

What does this mean?

What are the Possible Causes of the DTC U1878 Chevrolet?

Faulty Battery Energy Control Module
Battery Energy Control Module harness is open or shorted
Battery Energy Control Module circuit poor electrical connection

How to Fix the DTC U1878 Chevrolet?

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 U1878 Chevrolet 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.

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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 U1878 Chevrolet Code

1. What does the OBDII code U1878 mean in a Chevrolet?

The U1878 code indicates that the Drive Motor B Control Module has lost communication with the Battery Energy Control Module.

2. What are the common symptoms of the U1878 code?

Symptoms may include the Check Engine Light or other warning lights turning on, reduced vehicle performance, or issues with hybrid or electric motor operation.

3. What causes the U1878 code to appear?

This code is usually caused by issues such as faulty wiring or connectors, a malfunctioning Drive Motor B Control Module, a defective Battery Energy Control Module, or network communication problems.

4. How do I diagnose the U1878 code on my Chevrolet?

Start by inspecting the wiring and connectors between the Drive Motor B Control Module and the Battery Energy Control Module. Use a scan tool to check for additional codes and verify communication on the CAN bus network.

5. Can I drive my Chevrolet with the U1878 code active?

It is not recommended to drive with this code active, as it may lead to reduced performance or further damage to the electric or hybrid drive components.

6. How do I fix the U1878 code?

Repairs may include repairing or replacing damaged wiring or connectors, reprogramming the control modules, or replacing a faulty Drive Motor B or Battery Energy Control Module.

7. How much does it cost to repair the U1878 code?

Repair costs vary depending on the root cause but may range from $150 for wiring repairs to over $1,000 if a module requires replacement and reprogramming.

8. Can a low battery cause the U1878 code?

Yes, a weak or failing 12V battery can sometimes cause communication issues between modules, triggering this code.

9. Is the U1878 code specific to Chevrolet hybrid or electric vehicles?

Yes, this code is typically found in Chevrolet hybrid or electric models that rely on communication between the Drive Motor Control Module and the Battery Energy Control Module.

10. Do I need to reset the system after fixing the U1878 code?

Yes, after completing the repairs, clear the code with an OBDII scanner and test drive the vehicle to ensure the issue does not return.