AutoCodes – RAM – B2104 RAM

B2104 RAM Code - Ignition Unlock Run/Start Control Circuit Low

Quick Answer

The Front Control Module monitors the Ignition Unlock Run/Start Control Circuit. Common causes include Faulty Shifter Lever Assembly, Shifter Lever Assembly harness is open or shorted, Shifter Lever Assembly 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: B2104 RAM indicates Ignition Unlock Run/Start Control Circuit Low.
Common causes: Common causes include Faulty Shifter Lever Assembly, Shifter Lever Assembly harness is open or shorted, Shifter Lever Assembly 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 698

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
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Code B2104 RAM Description

The Front Control Module monitors the Ignition Unlock Run/Start Control Circuit. The Front Control Module will set this Diagnostic Trouble Code (DTC) within 500ms if the ignition unlock run/start circuit voltage is less than the expected value.

OBDII Code B2104 RAM - Ignition Unlock Run/Start Control Circuit Low - AutoCodes.com — B2104 RAM Code - Ignition Unlock Run/Start Control Circuit Low

What does this mean?

What are the Possible Causes of the DTC B2104 RAM?

Faulty Shifter Lever Assembly
Shifter Lever Assembly harness is open or shorted
Shifter Lever Assembly circuit poor electrical connection
Faulty Front Control Module (FCM)

How to Fix the DTC B2104 RAM?

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 B2104 RAM 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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Need Help with the Code?

Get the B2104 RAM 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 B2104 RAM Code

1. What does the OBDII code B2104 mean on a RAM vehicle?

The B2104 code indicates an issue with the Ignition Unlock Run/Start Control Circuit being in a low voltage condition.

2. What are common symptoms of the B2104 code in a RAM?

Symptoms may include difficulty starting the vehicle, unresponsive ignition switch, or the inability to turn the key to certain positions.

3. What causes the B2104 code to appear?

Common causes include a faulty ignition switch, damaged wiring or connectors in the ignition circuit, or a malfunctioning ignition relay.

4. How do I diagnose the B2104 code on a RAM?

Start by inspecting the ignition switch, wiring, and related connectors for damage or corrosion. Use a multimeter to check for proper voltage in the circuit.

5. Can I drive my RAM with the B2104 code present?

Driving may be possible, but the ignition system could fail completely, leaving you stranded. Itâ€™s best to address the issue promptly.

6. How do I fix the B2104 code in my RAM?

Repairs may include replacing the ignition switch, repairing damaged wiring, or replacing the ignition relay if found faulty.

7. How much does it cost to fix the B2104 code on a RAM?

Repair costs vary, but replacing an ignition switch typically ranges from $150 to $300, depending on parts and labor.

8. Can a weak battery cause the B2104 code?

Yes, a weak or failing battery can cause voltage issues in the ignition circuit, potentially triggering the B2104 code.

9. Will clearing the B2104 code fix the problem?

Clearing the code may temporarily turn off the warning, but the underlying issue must be fixed to prevent the code from returning.

10. Do I need a professional to fix the B2104 code on my RAM?

While some repairs like checking wiring can be done by a skilled DIYer, diagnosing and fixing ignition system issues may require professional tools and expertise.