AutoCodes – Mercury – B1508 Mercury

B1508 Mercury Code - Flash To Pass Switch Circuit Open

Quick Answer

The Smart Junction Box (SJB) sends reference signals to the headlamp switch through circuits. Common causes include Faulty Headlamp Switch, Headlamp Switch harness is open or shorted, Headlamp Switch 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: B1508 Mercury indicates Flash To Pass Switch Circuit Open.
Common causes: Common causes include Faulty Headlamp Switch, Headlamp Switch harness is open or shorted, Headlamp Switch 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 632

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 Apr 29, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1508 Mercury Description

The Smart Junction Box (SJB) sends reference signals to the headlamp switch through circuits. When the headlamp switch is placed in the HEADLAMPS ON position, the voltage signal is routed to ground through the circuit. If the SJB detects a fault with the headlamp switch inputs, the SJB turns the exterior lamps on by default. When the SJB detects the headlamp switch in the HEADLAMPS ON position and the multifunction switch in the LOW BEAM position, the SJB sends voltage through circuits to the low beam headlamps. When the SJB detects the headlamp switch in the HEADLAMPS ON position and the multifunction switch in the HIGH BEAM position, the SJB sends voltage through circuits to the high beam headlamps. The SJB sends a reference signal to the multifunction switch through circuits CLF27 (GN/BN) and CLF17 (WH/OG). When the multifunction switch is placed in the FLASH-TO-PASS or HIGH BEAM position, the voltage signal is routed to ground. When the SJB detects a request for the flash-to-pass, the SJB sends voltage to the high beam headlamps. The OBDII codes when the SJB detects a short to ground from the flash-to-pass input circuit.

OBDII Code B1508 Mercury - Flash To Pass Switch Circuit Open - AutoCodes.com — B1508 Mercury Code - Flash To Pass Switch Circuit Open

What does this mean?

What are the Possible Causes of the DTC B1508 Mercury?

Faulty Headlamp Switch
Headlamp Switch harness is open or shorted
Headlamp Switch circuit poor electrical connection
Faulty Smart Junction Box (SJB)

How to Fix the DTC B1508 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 B1508 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.

Need more information about the B1508 Mercury code?

Need more information on how to fix the B1508 Mercury code? Get Access to Factory Service Manuals

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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 B1508 Mercury Code

1. What are the common symptoms of OBDII code B1508 (Mercury) Flash To Pass Switch Circuit Open?

- The common symptoms include the inability to flash the high beams using the flash to pass switch on the vehicle's steering column.

2. What are the possible causes of the Flash To Pass Switch Circuit Open OBDII code (B1508) in a Mercury vehicle?

- The code B1508 can be triggered by a faulty flash to pass switch, damaged wiring in the circuit, or a defective control module.

3. How can I diagnose the Flash To Pass Switch Circuit Open issue in my Mercury vehicle?

- To diagnose the issue, you can start by inspecting the flash to pass switch for any visible damage. You can also perform a continuity test on the circuit wiring and check the control module for proper functioning.

4. Can a DIY enthusiast repair the Flash To Pass Switch Circuit Open problem in a Mercury vehicle?

- Depending on your mechanical skills and knowledge, you may be able to repair the issue yourself by replacing the faulty flash to pass switch or repairing the damaged wiring. However, if you are unsure, it is recommended to seek professional help.

5. Is it safe to continue driving with the B1508 OBDII code (Mercury) triggered?

- While the B1508 code may not affect the overall drivability of the vehicle, it is recommended to address the issue promptly to ensure the proper functioning of the flash to pass switch, especially in low visibility conditions.

6. How much does it typically cost to repair the Flash To Pass Switch Circuit Open issue in a Mercury vehicle?

- The cost of repairing the B1508 code can vary depending on the specific cause of the issue, the labor rates in your area, and whether you choose to repair it yourself or take it to a professional mechanic. It is advisable to get a few quotes for an accurate estimate.

7. Can a malfunctioning flash to pass switch cause other electrical problems in a Mercury vehicle?

- While the primary symptom of a faulty flash to pass switch is the inability to flash the high beams, it is possible for a malfunctioning switch to cause other related electrical issues in the vehicle. Therefore, it is essential to address the problem promptly.

8. Are there any preventive measures to avoid triggering the B1508 OBDII code in a Mercury vehicle?

- Regularly inspecting the flash to pass switch and ensuring it is in good working condition can help prevent the occurrence of the B1508 code. Additionally, avoiding excessive force when using the switch can help prolong its lifespan.

9. Can extreme weather conditions cause the Flash To Pass Switch Circuit Open issue in a Mercury vehicle?

- Extreme weather conditions, such as temperature fluctuations or moisture exposure, can potentially contribute to the failure of electrical components like the flash to pass switch, leading to the triggering of the B1508 code.

10. How long does it typically take to repair the Flash To Pass Switch Circuit Open issue in a Mercury vehicle?

- The repair time for the B1508 code can vary depending on the complexity of the issue and the availability of parts. In general, a skilled mechanic can diagnose and repair the problem within a few hours to a day.