AutoCodes – Generic – U1888

U1888 Code - Hybrid Control Module Lost Communication With Energy Storage Control Module

Quick Answer

Modules connected to the class 2 and high-speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Energy Storage Control Module (ESCM), Energy Storage Control Module harness is open or shorted, Energy Storage 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: U1888 indicates Hybrid Control Module Lost Communication With Energy Storage Control Module.
Common causes: Common causes include Faulty Energy Storage Control Module (ESCM), Energy Storage Control Module harness is open or shorted, Energy Storage 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 3,761

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 U1888 Description

Modules connected to the class 2 and 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 modules. The Diagnostic Trouble Code (DTC) is reported on a class 2 link to the scan tool by Powertrain Control Module (PCM) even if they may be set by different modules. The DTC will set when a node alive message has not been received from an identified module within the last 5 seconds after establishing class 2 serial data communication, or a supervised high-speed GMLAN message has not been received.

OBDII Code U1888 - Hybrid Control Module Lost Communication With Energy Storage Control Module - AutoCodes.com — U1888 Code - Hybrid Control Module Lost Communication With Energy Storage Control Module

What does this mean?

What are the Possible Causes of the DTC U1888?

Faulty Energy Storage Control Module (ESCM)
Energy Storage Control Module harness is open or shorted
Energy Storage Control Module circuit poor electrical connection
Faulty Hybrid Control Module (HCM)

How to Fix the DTC U1888?

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 U1888 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 U1888 code?

Need more information on how to fix the U1888 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1888 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U1888 Buick — Hybrid Control Module Lost Communication With Energy Storage Control Module
U1888 Cadillac — Hybrid Control Module Lost Communication With Energy Storage Control Module
U1888 Chevrolet — Hybrid Control Module Lost Communication With Energy Storage Control Module
U1888 GMC — Hybrid Control Module Lost Communication With Energy Storage Control Module

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 U1888 Code

What does the OBDII code U1888 indicate?

U1888 indicates that there is a communication issue between the Hybrid Control Module (HCM) and the Energy Storage Control Module (ESCM) in a hybrid vehicle.

What are common symptoms associated with the U1888 code?

Common symptoms include warning lights on the dashboard, reduced engine power, decreased fuel efficiency, and potential issues with hybrid system performance.

What could cause the U1888 code to set?

Causes may include damaged wiring or connectors between the HCM and ESCM, a faulty HCM or ESCM, software issues, or a weak battery affecting the communication.

Can I drive my vehicle if the U1888 code is present?

While it may be possible to drive the vehicle, it is not recommended as it could lead to reduced performance and further damage to the hybrid system. Itâ€™s best to have it diagnosed and repaired promptly.

How can I diagnose the U1888 code?

Start by using an OBDII scanner to confirm the code. Then, visually inspect the wiring and connectors for damage, check for software updates for the HCM and ESCM, and test the modulesâ€™ functionality.

What repairs are typically needed for the U1888 code?

Repairs may involve repairing or replacing damaged wiring or connectors, updating the software in the HCM or ESCM, or replacing a faulty module.

Is it possible to reset the U1888 code after repairs?

Yes, after addressing the underlying issue, you can clear the code using an OBDII scanner. However, itâ€™s important to ensure the problem is resolved before resetting.

How can I prevent the U1888 code from recurring?

Regular maintenance of the hybrid system, including inspections of wiring and connections, keeping the battery in good condition, and ensuring software is up to date can help prevent recurrence.

What should I do if Iâ€™m unable to fix the U1888 code myself?

If you cannot resolve the issue, itâ€™s advisable to take the vehicle to a qualified hybrid technician or dealership that specializes in hybrid systems for a thorough diagnosis and repair.