AutoCodes – Mercury – B2045 Mercury

B2045 Mercury Code - Left Rear Stop Lamp Circuit Open

Quick Answer

When the brake pedal is applied, the stoplamp switch routes voltage to the Smart Junction Box (SJB) and the high mounted stoplamp. Common causes include Faulty High Mounted Stoplamp, High Mounted Stoplamp harness is open or shorted, High Mounted Stoplamp 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: B2045 Mercury indicates Left Rear Stop Lamp Circuit Open.
Common causes: Common causes include Faulty High Mounted Stoplamp, High Mounted Stoplamp harness is open or shorted, High Mounted Stoplamp 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 489

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 Feb 26, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B2045 Mercury Description

When the brake pedal is applied, the stoplamp switch routes voltage to the Smart Junction Box (SJB) and the high mounted stoplamp. When the SJB detects the brake pedal is applied, the SJB provides voltage to the Left (LH) and Right (RH) rear stoplamps. The Diagnostic Trouble Code (DTC) sets when the SJB detects an open from the LH rear stop/turn lamp voltage supply circuit.

OBDII Code B2045 Mercury - Left Rear Stop Lamp Circuit Open - AutoCodes.com — B2045 Mercury Code - Left Rear Stop Lamp Circuit Open

What does this mean?

What are the Possible Causes of the DTC B2045 Mercury?

Faulty High Mounted Stoplamp
High Mounted Stoplamp harness is open or shorted
High Mounted Stoplamp circuit poor electrical connection
Faulty Bulb Holder
Faulty Smart Junction Box (SJB)

How to Fix the DTC B2045 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 B2045 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 B2045 Mercury Code

1. What are the common symptoms of OBDII code B2045 Mercury (Left Rear Stop Lamp Circuit Open)?

- The common symptoms include the left rear stop lamp not illuminating when the brakes are applied, causing a safety hazard.

2. What are the possible causes of OBDII code B2045 Mercury?

- The code B2045 Mercury typically occurs due to a faulty left rear stop lamp bulb, a damaged wiring harness, or a faulty stop lamp switch.

3. How can I diagnose the issue related to OBDII code B2045 Mercury?

- To diagnose the issue, you can start by visually inspecting the left rear stop lamp bulb and its connections. Check the wiring harness for any visible damage or corrosion. You can also use a multimeter to test the continuity of the circuit.

4. What are some repair tips for fixing OBDII code B2045 Mercury?

- If the issue is with the left rear stop lamp bulb, simply replacing the bulb may resolve the code. If the problem lies in the wiring harness, repairing or replacing the damaged section may be necessary. Additionally, checking and adjusting the stop lamp switch can also help resolve the issue.

5. Can OBDII code B2045 Mercury be a serious issue?

- While the code itself may not be a serious mechanical problem, it can pose a safety risk by affecting the visibility of the vehicle's brake lights. It is important to address this issue promptly to ensure proper brake light functionality.

6. Is it safe to continue driving with OBDII code B2045 Mercury unresolved?

- It is not recommended to continue driving with OBDII code B2045 Mercury unresolved, as it can compromise the visibility of your vehicle's brake lights, potentially leading to rear-end collisions or other safety hazards.

7. Can a DIY enthusiast fix OBDII code B2045 Mercury on their own?

- Depending on the cause of the issue, DIY enthusiasts with basic automotive repair skills may be able to fix OBDII code B2045 Mercury by replacing a faulty bulb, repairing a damaged wiring harness, or adjusting the stop lamp switch.

8. Will resetting the OBDII system clear the B2045 Mercury code?

- Resetting the OBDII system may temporarily clear the B2045 Mercury code, but if the underlying issue such as a faulty bulb or wiring problem is not addressed, the code is likely to reappear.

9. How can I prevent OBDII code B2045 Mercury from occurring again in the future?

- To prevent OBDII code B2045 Mercury from occurring again, regularly inspect and maintain the vehicle's stop lamps, wiring harness, and stop lamp switch. Promptly replacing any faulty components can help prevent the code from reoccurring.

10. Does OBDII code B2045 Mercury affect the vehicle's overall performance?

- OBDII code B2045 Mercury does not directly impact the vehicle's overall performance, but it does affect the safety features by compromising the functionality of the left rear stop lamp.