AutoCodes – Generic – B1E21

B1E21 Code - Backup Battery Circuit Voltage Below Threshold

Quick Answer

The Emergency Assistance Module (EAM) monitors the Backup Battery Circuit. Common causes include Faulty Backup Battery, Backup Battery harness is open or shorted, Backup Battery 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: B1E21 indicates Backup Battery Circuit Voltage Below Threshold.
Common causes: Common causes include Faulty Backup Battery, Backup Battery harness is open or shorted, Backup Battery 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 2,173

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 Sep 03, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1E21 Description

The Emergency Assistance Module (EAM) monitors the Backup Battery Circuit. The EAM sets the OBDII code when it detects a low backup battery.

OBDII Code B1E21 - Backup Battery Circuit Voltage Below Threshold - AutoCodes.com — B1E21 Code - Backup Battery Circuit Voltage Below Threshold

What does this mean?

What are the Possible Causes of the DTC B1E21?

Faulty Backup Battery
Backup Battery harness is open or shorted
Backup Battery circuit poor electrical connection
Faulty Emergency Assistance Module (EAM)

How to Fix the DTC B1E21?

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 B1E21 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 B1E21 code?

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Need Help with the Code?

Get the B1E21 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B1E21 Chrysler — Backup Battery Circuit Voltage Below Threshold
B1E21 Dodge — Backup Battery Circuit Voltage Below Threshold
B1E21 Jeep — Backup Battery Circuit Voltage Below Threshold
B1E21 RAM — Backup Battery Circuit Voltage Below Threshold

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 B1E21 Code

1. What are the common symptoms of OBDII code B1E21 (Backup Battery Circuit Voltage Below Threshold)?

The common symptoms of code B1E21 include the illumination of the check engine light on the dashboard and possible issues with the vehicle's electrical system.

2. What can cause the OBDII code B1E21 to trigger?

The code B1E21 is typically triggered when the voltage in the backup battery circuit falls below the threshold set by the vehicle's computer system.

3. How serious is the OBDII code B1E21?

While code B1E21 may not cause immediate drivability issues, it should be addressed promptly to prevent potential electrical system malfunctions or starting problems.

4. What should I do if I get the OBDII code B1E21?

If you receive code B1E21, it is recommended to have a professional mechanic diagnose the issue to determine the exact cause and necessary repairs.

5. Can I still drive my vehicle with the OBDII code B1E21 present?

It is generally safe to drive the vehicle with the B1E21 code, but it is advisable to address the issue as soon as possible to prevent any further electrical problems.

6. How can I repair the Backup Battery Circuit Voltage Below Threshold issue associated with OBDII code B1E21?

Repairing the B1E21 code may involve checking the backup battery circuit for any faults, replacing damaged components, and ensuring proper voltage levels in the system.

7. Will resetting the OBDII code B1E21 make it go away permanently?

Resetting the code may temporarily turn off the check engine light, but if the underlying issue is not fixed, the code is likely to reappear.

8. Is it possible to prevent OBDII code B1E21 from occurring in the future?

Regular maintenance checks, including inspecting the vehicle's electrical system, can help prevent issues like code B1E21 from occurring.

9. Can a DIY enthusiast fix the OBDII code B1E21 at home?

While some DIYers may be able to address simple electrical issues related to code B1E21, it is best to consult a professional mechanic for a proper diagnosis and repair.

10. How much does it typically cost to repair the Backup Battery Circuit Voltage Below Threshold issue associated with OBDII code B1E21?

The cost of repairing code B1E21 can vary depending on the specific cause of the problem, but it may involve labor costs and the price of any replacement parts needed.