AutoCodes – Chevrolet – U1891 Chevrolet

U1891 Chevrolet Code - Hybrid Control Module Lost Communication With Instrument Panel Cluster

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 Instrument Panel Cluster (IPC), Instrument Panel Cluster harness is open or shorted, Instrument Panel Cluster 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: U1891 Chevrolet indicates Hybrid Control Module Lost Communication With Instrument Panel Cluster.
Common causes: Common causes include Faulty Instrument Panel Cluster (IPC), Instrument Panel Cluster harness is open or shorted, Instrument Panel Cluster 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 1,104

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 Jun 08, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1891 Chevrolet 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 U1891 Chevrolet - Hybrid Control Module Lost Communication With Instrument Panel Cluster - AutoCodes.com — U1891 Chevrolet Code - Hybrid Control Module Lost Communication With Instrument Panel Cluster

What does this mean?

What are the Possible Causes of the DTC U1891 Chevrolet?

Faulty Instrument Panel Cluster (IPC)
Instrument Panel Cluster harness is open or shorted
Instrument Panel Cluster circuit poor electrical connection
Faulty Hybrid Control Module (HCM)

How to Fix the DTC U1891 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 U1891 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 U1891 Chevrolet Code

1. What does the OBDII code U1891 mean on a Chevrolet?

The U1891 code indicates that the Hybrid Control Module has lost communication with the Instrument Panel Cluster (IPC).

2. What are the common symptoms of the U1891 code?

Symptoms may include warning lights on the dashboard, inaccurate or non-functional gauges, hybrid system performance issues, or a lack of communication with diagnostic tools.

3. What causes the U1891 code on a Chevrolet?

Common causes include faulty wiring or connectors, a malfunctioning Instrument Panel Cluster, a defective Hybrid Control Module, or network communication issues within the vehicle.

4. Can I drive my Chevrolet with the U1891 code?

Driving with the U1891 code is not recommended, as it may lead to inaccurate instrument readings or compromised hybrid system performance, which could affect vehicle safety.

5. How do I diagnose the U1891 code on a Chevrolet?

Diagnosis involves checking for damaged wiring, loose or corroded connectors, ensuring proper module grounding, and using a scan tool to test communication between modules.

6. What repairs are needed to fix the U1891 code?

Repairs may include repairing or replacing damaged wiring, cleaning or reconnecting connectors, reprogramming the affected modules, or replacing a faulty Hybrid Control Module or Instrument Panel Cluster.

7. Can a low battery cause the U1891 code?

Yes, a weak or failing battery can cause communication issues between modules, potentially triggering the U1891 code.

8. How much does it cost to fix the U1891 code on a Chevrolet?

Repair costs vary depending on the cause, ranging from $100 to $1,000, depending on whether wiring repairs or module replacements are necessary.

9. Will clearing the U1891 code with a scan tool solve the problem?

Clearing the code may temporarily remove the warning, but if the underlying issue isnâ€™t resolved, the code will likely return.

10. Can the U1891 code be caused by a software issue?

Yes, outdated or corrupted software in the Hybrid Control Module or Instrument Panel Cluster can potentially cause communication errors leading to the U1891 code.