AutoCodes – Lincoln – B1508 Lincoln

B1508 Lincoln 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 Lincoln 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 670

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
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

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

What does this mean?

What are the Possible Causes of the DTC B1508 Lincoln?

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 Lincoln?

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 Lincoln 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 Lincoln code?

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

Need Help with the Code?

Get the B1508 Lincoln 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 B1508 Lincoln Code

1. What are the common symptoms of OBDII code B1508 in a Lincoln related to the Flash To Pass Switch Circuit Open?

- The common symptoms include the flash to pass switch not functioning properly, the high beams not engaging when the switch is activated, and the dashboard indicator light illuminating.

2. What are the possible causes of the Flash To Pass Switch Circuit Open code B1508 in a Lincoln?

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

3. How can I diagnose the Flash To Pass Switch Circuit Open issue in my Lincoln when code B1508 is present?

- Diagnose the issue by inspecting the flash to pass switch for physical damage, checking the wiring and connectors for any breaks or corrosion, and using a multimeter to test for continuity in the circuit.

4. Can I continue driving my Lincoln with the B1508 code related to the Flash To Pass Switch Circuit Open?

- It is generally safe to drive the vehicle with this issue, but you may experience inconvenience due to the malfunctioning flash to pass switch and the inability to engage high beams.

5. What are some repair tips for fixing the Flash To Pass Switch Circuit Open problem in a Lincoln?

- Repair tips include replacing the flash to pass switch if faulty, repairing or replacing damaged wiring and connectors, and resetting the control module after making necessary repairs.

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

- The cost of repairing the issue can vary depending on the root cause, but it may range from $100 to $300 for parts and labor at a dealership or repair shop.

7. Is it possible to reset the B1508 code related to the Flash To Pass Switch Circuit Open without professional help?

- Yes, you can attempt to reset the code by disconnecting the car battery for a few minutes and then reconnecting it. However, the underlying issue should still be diagnosed and repaired to prevent the code from reappearing.

8. Can extreme weather conditions affect the Flash To Pass Switch Circuit Open problem in a Lincoln?

- Yes, extreme weather conditions such as excessive heat or moisture can potentially worsen the issue by causing electrical components to malfunction or corrode more quickly.

9. Will the B1508 code related to the Flash To Pass Switch Circuit Open cause my Lincoln to fail a state emissions test?

- The code B1508 itself may not cause the vehicle to fail an emissions test, but it is recommended to address any OBDII codes to ensure the vehicle is running optimally and to prevent any potential issues from escalating.

10. How can I prevent the Flash To Pass Switch Circuit Open issue from recurring in my Lincoln?

- To prevent the issue from recurring, perform regular maintenance checks on the vehicle's electrical system, avoid using the flash to pass switch excessively, and address any warning lights or symptoms promptly.