AutoCodes – Generic – B1804

B1804 Code - Lamp Turn Signal Rear Output Circuit Short To Battery

Quick Answer

The Body Control Module (BCM) monitors the Lamp Turn Signal Rear. Common causes include Faulty Lamp Turn Signal Rear, Lamp Turn Signal Rear harness is open or shorted, Lamp Turn Signal Rear 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: B1804 indicates Lamp Turn Signal Rear Output Circuit Short To Battery.
Common causes: Common causes include Faulty Lamp Turn Signal Rear, Lamp Turn Signal Rear harness is open or shorted, Lamp Turn Signal Rear 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 6,182

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 Jul 02, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1804 Description

The Body Control Module (BCM) monitors the Lamp Turn Signal Rear. The BCM sets the OBDII code when the Lamp Turn Signal Rear is not to factory specifications.

OBDII Code B1804 - Lamp Turn Signal Rear Output Circuit Short To Battery - AutoCodes.com — B1804 Code - Lamp Turn Signal Rear Output Circuit Short To Battery

What does this mean?

What are the Possible Causes of the DTC B1804?

Faulty Lamp Turn Signal Rear
Lamp Turn Signal Rear harness is open or shorted
Lamp Turn Signal Rear circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B1804?

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 B1804 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 B1804 code?

Need more information on how to fix the B1804 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1804 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B1804 Chrysler — Driver Door Lock/Unlock Switch Circuit Stuck Unlock
B1804 Dodge — Driver Door Lock/Unlock Switch Circuit Stuck Unlock
B1804 Jeep — Driver Door Lock/Unlock Switch Circuit Stuck Unlock
B1804 RAM — Driver Door Lock/Unlock Switch Circuit Stuck Unlock

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 B1804 Code

1. What are the common symptoms of OBDII code B1804?

- The common symptoms include the rear turn signal lamp staying on continuously, even when the turn signal is not activated.

2. What causes the OBDII code B1804 to occur?

- The code B1804 is triggered when there is a short circuit between the rear turn signal lamp output circuit and the battery.

3. How can I diagnose the cause of OBDII code B1804?

- To diagnose this code, you can use a multimeter to check for continuity and voltage in the rear turn signal lamp circuit. Inspect the wiring for any signs of damage or corrosion.

4. Is it safe to continue driving with OBDII code B1804?

- It is not recommended to continue driving with this code present, as it can affect the proper function of your turn signals and pose a safety hazard on the road.

5. How can I repair OBDII code B1804?

- To repair this code, you will need to locate and repair the short circuit between the rear turn signal lamp output circuit and the battery. This may involve repairing or replacing damaged wiring or components.

6. Can a DIY enthusiast fix OBDII code B1804 at home?

- If you have experience with automotive electrical systems and access to the necessary tools, you may be able to diagnose and repair this code at home. However, if you are unsure, it is best to seek professional help.

7. Does OBDII code B1804 affect other vehicle systems?

- While this code specifically relates to the rear turn signal lamp circuit, electrical issues in one part of the vehicle can sometimes affect other systems. It's essential to address this code promptly to prevent further problems.

8. How long does it typically take to repair OBDII code B1804?

- The repair time for this code can vary depending on the exact cause of the short circuit and the accessibility of the wiring. In general, it may take anywhere from 1 to 3 hours to diagnose and repair the issue.

9. Can weather conditions impact the occurrence of OBDII code B1804?

- Extreme weather conditions, such as heavy rain or snow, can sometimes exacerbate electrical issues in a vehicle, including the occurrence of a short circuit leading to code B1804.

10. What should I do if OBDII code B1804 keeps recurring after repair?

- If the code keeps coming back after repair, it indicates that the underlying issue was not fully resolved. In such cases, it's best to recheck the wiring and connections thoroughly to ensure there are no hidden faults.