AutoCodes – Mercury – B12C2 Mercury

B12C2 Mercury Code - Puddle Lamp Circuit Short To Ground

Quick Answer

The cargo lamp illuminates when the courtesy lamps illuminate. Common causes include Blown High Mounted Stop Lamp Fuse, Faulty High Mounted Stop Lamp, High Mounted Stop Lamp harness is open or shorted. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means: B12C2 Mercury indicates Puddle Lamp Circuit Short To Ground.
Common causes: Common causes include Blown High Mounted Stop Lamp Fuse, Faulty High Mounted Stop Lamp, High Mounted Stop Lamp harness is open or shorted.
Severity: Low - monitor the vehicle and repair when practical.
Can I drive?: The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

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Code Popularity 788

How popular is this code, among other codes? Low

Repair Importance Level

Low (Monitor) (1 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Nov 29, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B12C2 Mercury Description

The cargo lamp illuminates when the courtesy lamps illuminate. The Body Control Module (BCM) uses a separate output circuit that supplies voltage to the cargo lamp. The cargo lamp shares the ground circuit with the High Mounted Stop Lamp. The puddle lamps (if equipped) share the voltage supply with the cargo lamp. This Diagnostic Trouble Code (DTC) sets when the BCM detects a short to ground from the cargo lamp output circuit.

OBDII Code B12C2 Mercury - Puddle Lamp Circuit Short To Ground - AutoCodes.com — B12C2 Mercury Code - Puddle Lamp Circuit Short To Ground

What does this mean?

What are the Possible Causes of the DTC B12C2 Mercury?

Blown High Mounted Stop Lamp Fuse
Faulty High Mounted Stop Lamp
High Mounted Stop Lamp harness is open or shorted
High Mounted Stop Lamp circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B12C2 Mercury?

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 B12C2 Mercury 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 B12C2 Mercury Code

1. What are common symptoms of an OBDII code B12C2 Mercury (Puddle Lamp Circuit Short To Ground)?

- Common symptoms include inoperative or flickering puddle lamps, illuminated warning lights on the dashboard, and potential electrical issues.

2. What can cause the OBDII code B12C2 Mercury (Puddle Lamp Circuit Short To Ground)?

- Causes may include a short to ground in the puddle lamp circuit, damaged wiring or connectors, water intrusion, or faulty control modules.

3. How do I diagnose the OBDII code B12C2 Mercury (Puddle Lamp Circuit Short To Ground)?

- Diagnosis involves inspecting the wiring and connectors for damage, checking for water intrusion, testing the circuit for shorts, and using a scan tool to pinpoint the issue.

4. Can I drive my Mercury with the OBDII code B12C2 (Puddle Lamp Circuit Short To Ground)?

- It is generally safe to drive the vehicle with this code, but it is recommended to address the issue promptly to avoid potential electrical problems or safety hazards.

5. How do I repair the OBDII code B12C2 Mercury (Puddle Lamp Circuit Short To Ground)?

- Repair steps may involve repairing or replacing damaged wiring, fixing connectors, addressing water intrusion issues, or replacing faulty components like control modules.

6. Are there any DIY tips for fixing the OBDII code B12C2 Mercury (Puddle Lamp Circuit Short To Ground)?

- DIY tips include checking and cleaning connectors, ensuring proper wiring routing to prevent chafing, and using dielectric grease to protect electrical connections.

7. Is it necessary to reset the OBDII code B12C2 Mercury (Puddle Lamp Circuit Short To Ground) after repair?

- Yes, it is essential to clear the code using an OBDII scan tool after repairing the issue to reset the warning lights and ensure proper functioning of the system.

8. Can a faulty puddle lamp itself trigger the OBDII code B12C2 Mercury (Puddle Lamp Circuit Short To Ground)?

- Yes, a faulty puddle lamp can sometimes cause a short to ground in the circuit, leading to the triggering of the B12C2 trouble code.

9. How much does it cost to repair the OBDII code B12C2 Mercury (Puddle Lamp Circuit Short To Ground) at a dealership?

- Repair costs at a dealership may vary depending on the exact cause of the issue, but it typically involves diagnostic fees, labor costs, and the price of any necessary parts.

10. What are the long-term effects of ignoring the OBDII code B12C2 Mercury (Puddle Lamp Circuit Short To Ground)?

- Ignoring this code may lead to further electrical problems, potential short circuits, and decreased visibility at night due to malfunctioning puddle lamps.