AutoCodes – Dodge – B2120 Dodge

B2120 Dodge Code - Ignition Run/Acc/Pad Control Circuit Open

Quick Answer

The Front Control Module monitors the Ignition Run/ACC/Pad Control Circuit. Common causes include Faulty Accessory Delay Relay, Accessory Delay Relay harness is open or shorted, Accessory Delay Relay 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: B2120 Dodge indicates Ignition Run/Acc/Pad Control Circuit Open.
Common causes: Common causes include Faulty Accessory Delay Relay, Accessory Delay Relay harness is open or shorted, Accessory Delay Relay 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 1,810

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 17, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code B2120 Dodge Description

The Front Control Module monitors the Ignition Run/ACC/Pad Control Circuit. The Front Control Module will set this Diagnostic Trouble Code (DTC) within 500ms if the Ignition Accessory Delay Relay Control circuit is open.

OBDII Code B2120 Dodge - Ignition Run/Acc/Pad Control Circuit Open - AutoCodes.com — B2120 Dodge Code - Ignition Run/Acc/Pad Control Circuit Open

What does this mean?

What are the Possible Causes of the DTC B2120 Dodge?

Faulty Accessory Delay Relay
Accessory Delay Relay harness is open or shorted
Accessory Delay Relay circuit poor electrical connection
Faulty Front Control Module (FCM)

How to Fix the DTC B2120 Dodge?

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 B2120 Dodge 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 B2120 Dodge code?

Need more information on how to fix the B2120 Dodge code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B2120 Dodge code diagnosed by a professional: Find a repair shop in your area

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 B2120 Dodge Code

1. What does the OBDII code B2120 mean for a Dodge vehicle?

The B2120 code indicates an open circuit issue in the Ignition Run/Accessory/Pad Control circuit, meaning there is a break or disconnection in the wiring or component responsible for these functions.

2. What are the common symptoms of the B2120 code in a Dodge?

Symptoms include the vehicle not starting, accessories like the radio or lights not functioning in the ACC position, or intermittent power loss to certain systems.

3. What causes the B2120 Ignition Run/Acc/Pad Control Circuit Open code?

The most common causes are damaged or corroded wiring, a faulty ignition switch, a blown fuse, or a malfunctioning ignition relay.

4. Can a bad ignition switch cause the B2120 code?

Yes, a faulty ignition switch can prevent proper connectivity in the Ignition Run/Acc/Pad circuit and trigger the B2120 code.

5. How is the B2120 code diagnosed?

A technician will inspect the ignition switch, wiring, fuses, and relays for damage or open circuits using a multimeter and may also check for loose or corroded connections.

6. Can I drive my Dodge with the B2120 code?

Driving with this code is not recommended as it may cause issues with starting the vehicle or lead to accessory power failures.

7. How do you fix the B2120 code in a Dodge vehicle?

Repairs include replacing damaged wiring, repairing loose or corroded connections, replacing a faulty ignition switch, or replacing a blown fuse or defective relay.

8. Will clearing the code fix the B2120 issue?

Clearing the code without addressing the underlying issue will not fix the problem; the code will likely reappear until the root cause is repaired.

9. How much does it typically cost to fix the B2120 code?

Repair costs vary but generally range from $100 to $300 depending on whether wiring repairs, ignition switch replacement, or other components are needed.

10. Can a DIYer fix the B2120 code?

If you have experience with automotive electrical systems and the proper tools, you may be able to fix minor wiring issues or replace a fuse. However, more complex repairs may require professional assistance.