B1568 — Lamp Headlamp High-Beam Circuit Open #

Note: The description of DTC B1568 may vary depending on the vehicle manufacturer (OEM). Always refer to your OEM service information for the exact definition and troubleshooting procedures.

• B1568 — Headlamp High Beam Circuit Open (Toyota, Lexus)
• B1568 — High Beam Lamp Circuit Open (Ford, Lincoln)
• B1568 — High Beam Headlamp Relay Circuit Open (Nissan, Infiniti)
• B1568 — High Beam Headlight Circuit Open (General Motors, GMC, Chevrolet)

Summary of code B1568 #

B1568 is a diagnostic trouble code (DTC) that indicates the control module has detected an open circuit in the headlamp high-beam circuit. This means the electrical pathway responsible for powering the high-beam headlights is interrupted, preventing normal function. The open circuit can result from wiring damage, faulty connectors, a bad relay, or even a failed high-beam bulb. Modern vehicles use complex multiplexed lighting systems; thus, even a simple open can trigger this code and disable high-beam operation. Prompt diagnosis is important for safety and for passing state vehicle inspections.

Common symptoms for code B1568 #

When code B1568 is active, you may notice issues with your high beams that are both obvious and subtle. While your vehicle might still operate normally otherwise, compromised headlight function could impact your night driving safety. Symptoms can include:

• High-beam headlamps do not turn on
• High-beam indicator light on the dashboard does not illuminate
• Warning messages or headlight malfunction lights on the instrument cluster
• Automatic high-beam function (if equipped) not working
• Other exterior lighting circuits may be affected in rare cases

Probable causes for code B1568 #

The most common causes of a B1568 code typically relate to the electrical path between the body control module (sometimes called the BCM) and the high-beam bulbs or relays. Understanding the most likely culprits can streamline your troubleshooting process:

1. Burned out or faulty high-beam headlamp bulb(s)
2. Open or damaged wiring harness (broken, corroded, or disconnected wires)
3. Faulty or loose headlamp connector
4. Defective high-beam relay or fuse
5. Malfunctioning headlamp switch or multi-function switch
6. Faulty body control module (rare)

Step-by-step diagnosis for code B1568 #

A systematic approach helps you pinpoint the root cause of the B1568 code without replacing parts blindly. Here’s a proven diagnostic path, starting with the simplest checks:

1. Verify the code with a scan tool and check for any other related DTCs.
2. Inspect the high-beam bulbs for continuity and obvious damage; replace if necessary.
3. Examine the headlamp connectors for corrosion, looseness, or bent pins.
4. Check the high-beam fuse and relay; swap with a known-good unit if possible.
5. Trace the wiring from the BCM to the headlamp for any visible damage, open circuits, or short circuits.
6. Test the headlamp switch/multi-function switch for proper operation using a multimeter.
7. If all else checks out, inspect the BCM for faults or consider reprogramming/flashing (OEM procedure).

Possible repairs for code B1568 #

Once you’ve identified the cause of the B1568 code, targeted repairs restore your high-beam functionality. Depending on your findings, solutions may include:

• Replace burned out or faulty high-beam bulbs
• Repair or replace damaged or corroded wiring harnesses
• Clean or replace faulty headlamp connectors
• Replace a defective high-beam relay or fuse
• Replace or repair the headlamp switch or multi-function switch
• Reprogram or replace the body control module as a last resort

Is it safe to drive with code B1568? #

No — driving with code B1568 is not recommended, especially at night or in low-visibility conditions. The code indicates your high-beam headlamps are not functioning, which can significantly reduce your ability to see and be seen on the road after dark. In some regions, non-functioning exterior lighting is grounds for a traffic violation or failed inspection. Addressing this issue promptly ensures your safety and compliance.

Vehicles most commonly affected by code B1568 #

While B1568 is a generic body code found across many makes, it is more frequently reported on vehicles equipped with advanced lighting systems or multiplexed wiring. Some of the most commonly affected brands include:

• Toyota (Camry, Corolla, Tacoma, Prius)
• Lexus (RX, ES, IS)
• Ford (F-150, Explorer, Fusion)
• Lincoln (MKZ, Navigator)
• Nissan (Altima, Rogue, Titan)
• Infiniti (Q50, QX60)
• General Motors (Chevrolet Silverado, GMC Sierra, Buick Enclave)

Common mistakes & best practices for code B1568 #

When troubleshooting B1568, technicians and DIYers sometimes fall into predictable traps. Avoid these pitfalls for an effective repair:

• Replacing bulbs without checking the fuse, relay, or wiring
• Overlooking corroded or loose connectors at the headlamp assembly
• Ignoring possible BCM-related issues on vehicles with multiplexed lighting
• Not verifying the repair by clearing the code and retesting the system
• Using non-OEM bulbs or connectors that may not meet proper specifications

Express FAQ for code B1568 #

Quick answers to the most common questions regarding B1568:

Q: Will replacing the high-beam bulb always fix code B1568?
A: Not always. While a faulty bulb is a common cause, wiring issues, relay failures, or a problem in the body control module can also trigger this code.

Q: Can a faulty headlight switch cause code B1568?
A: Yes, if the high-beam circuit inside the headlight or multi-function switch is open or has high resistance, it can prevent the high beams from operating and set this code.

Q: Is B1568 a safety concern?
A: Absolutely. Functional high beams are critical for night driving safety. Address this code as soon as possible to maintain visibility and legality.

If you’re unsure about tackling B1568 yourself, consult a qualified technician or your dealer’s service department. Proper diagnosis and repair will get you safely back on the road — and keep those high beams shining bright.