AutoCodes – Ford – B1508 Ford

B1508 Ford 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 Ford 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 938

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

What does this mean?

What are the Possible Causes of the DTC B1508 Ford?

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 Ford?

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 Ford 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 B1508 Ford Code

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

- The common symptoms include the inability to use the flash-to-pass feature on your Ford vehicle, along with a malfunction indicator light (MIL) on the dashboard.

2. What could cause the OBDII code B1508 Ford to trigger?

- The code B1508 Ford is typically triggered by a malfunction in the flash-to-pass switch circuit, often due to a damaged or open circuit in the wiring.

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

- You can start by visually inspecting the flash-to-pass switch and its wiring for any visible damage. Using a multimeter to test the continuity of the circuit can also help pinpoint the issue.

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

- Depending on your skill level and experience with automotive electrical systems, you may be able to repair the issue yourself by replacing the damaged wiring or switch. However, if you're unsure, it's best to seek professional help.

5. Is it safe to drive my Ford vehicle with the B1508 trouble code?

- While the code B1508 itself may not affect the drivability of your vehicle, it's important to address the underlying issue promptly to ensure all electrical systems are functioning correctly.

6. How much does it typically cost to repair the Flash To Pass Switch Circuit Open problem at a mechanic or dealership?

- The cost of repairing the Flash To Pass Switch Circuit Open issue can vary depending on the extent of the damage and the labor rates of the service provider. It's recommended to get a few quotes for comparison.

7. Are there any recalls or service bulletins related to OBDII code B1508 Ford?

- It's advisable to check with Ford or the National Highway Traffic Safety Administration (NHTSA) for any recalls or service bulletins related to the Flash To Pass Switch Circuit Open problem on your specific Ford model.

8. Can a faulty flash-to-pass switch cause other electrical issues in my Ford vehicle?

- While the Flash To Pass Switch Circuit Open issue may not directly cause other electrical problems, it's essential to address any malfunctioning components promptly to prevent potential issues down the line.

9. What are the steps to reset the OBDII code B1508 Ford after repairing the Flash To Pass Switch Circuit Open problem?

- Once you've fixed the Flash To Pass Switch Circuit Open problem, you can reset the trouble code using an OBDII scanner or by disconnecting the vehicle's battery for a few minutes to clear the stored codes.

10. How can I prevent the Flash To Pass Switch Circuit Open issue from occurring again in the future?

- To prevent a recurrence of the B1508 trouble code, it's essential to properly maintain your Ford vehicle's electrical system, including regular inspections of the flash-to-pass switch and wiring for any signs of wear or damage.