AutoCodes – Cadillac – U2621 Cadillac

U2621 Cadillac Code - Battery Energy Control Module Lost Communication With Hybrid/EV Battery Interface Control Module 9

Quick Answer

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Hybrid/EV Battery Interface Control Module 9, Hybrid/EV Battery Interface Control Module 9 harness is open or shorted, Hybrid/EV Battery Interface Control Module 9 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: U2621 Cadillac indicates Battery Energy Control Module Lost Communication With Hybrid/EV Battery Interface Control Module 9.
Common causes: Common causes include Faulty Hybrid/EV Battery Interface Control Module 9, Hybrid/EV Battery Interface Control Module 9 harness is open or shorted, Hybrid/EV Battery Interface Control Module 9 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 612

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 18, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U2621 Cadillac 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 scan tool does not communicate the Hybrid/EV Battery Interface Control Modules 9 on Battery Energy Control Module dedicated bus.
The Diagnostic Trouble Code (DTC) will set when there is no temperature report message from Hybrid/EV Battery Interface Control Modules 9 to Battery Energy Control Module within 4s.

OBDII Code U2621 Cadillac - Battery Energy Control Module Lost Communication With Hybrid/EV Battery Interface Control Module 9 - AutoCodes.com — U2621 Cadillac Code - Battery Energy Control Module Lost Communication With Hybrid/EV Battery Interface Control Module 9

What does this mean?

What are the Possible Causes of the DTC U2621 Cadillac?

Faulty Hybrid/EV Battery Interface Control Module 9
Hybrid/EV Battery Interface Control Module 9 harness is open or shorted
Hybrid/EV Battery Interface Control Module 9 circuit poor electrical connection
Faulty Battery Energy Control Module

How to Fix the DTC U2621 Cadillac?

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 U2621 Cadillac 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 U2621 Cadillac Code

1. What are common symptoms of OBDII code U2621 in a Cadillac?

- Common symptoms may include a check engine light, reduced hybrid/EV system performance, and potential issues with battery energy control.

2. What can cause the U2621 code to appear in a Cadillac?

- The U2621 code can be triggered by a communication failure between the Battery Energy Control Module and the Hybrid/EV Battery Interface Control Module 9.

3. How serious is the U2621 code in a Cadillac?

- The U2621 code typically indicates a communication issue between critical components of the hybrid/EV system, so it should be addressed promptly to avoid potential performance issues.

4. How can I diagnose the U2621 code in my Cadillac?

- Diagnosing the U2621 code usually involves using a professional OBDII scanner to retrieve the specific fault codes and then investigating the communication link between the mentioned modules.

5. Can I drive my Cadillac with the U2621 code present?

- It is recommended to avoid driving the vehicle with the U2621 code present to prevent any further damage to the hybrid/EV system until the issue is resolved.

6. What are some potential repair tips for the U2621 code in a Cadillac?

- Repair tips may include checking and repairing any damaged wiring or connectors between the Battery Energy Control Module and the Hybrid/EV Battery Interface Control Module 9.

7. How much does it typically cost to fix the U2621 code in a Cadillac?

- Repair costs for the U2621 code can vary depending on the labor rates and parts needed, but it's advisable to consult a professional mechanic for an accurate estimate.

8. Can I reset the U2621 code in my Cadillac by disconnecting the battery?

- While disconnecting the battery may reset the check engine light temporarily, it will not resolve the underlying communication issue between the modules causing the U2621 code.

9. Is the U2621 code specific to Cadillac vehicles only?

- The U2621 code is specific to Cadillac vehicles and relates to communication problems between the Battery Energy Control Module and the Hybrid/EV Battery Interface Control Module 9.

10. How can I prevent the U2621 code from reoccurring in my Cadillac?

- Regular maintenance checks, including inspecting the hybrid/EV system components and ensuring all connections are secure, can help prevent the U2621 code from reoccurring in your Cadillac.