B1568 — Lamp Headlamp High-Beam Circuit Open

B1568 — Lamp Headlamp High-Beam Circuit Open. A fault in the body electrical system. The car is usually drivable while you plan the repair. Typical causes: body control module (BCM) fault, damaged wiring in door jambs or wet areas, corroded or loose connectors.

body electrical

Is it safe to drive?

Short-term driving is OK Usually safe to drive — body codes rarely affect drivability. Exceptions: exterior lighting and wipers in bad weather, and central locking faults that can leave the car unsecured.

How to diagnose with an OBD scanner

  1. Read the code and freeze frame Connect an OBD2 scanner, confirm B1568 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many B0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the body electrical system for damage, corrosion, chafing or poor contact.
  4. Subsystem check Do a continuity test end-to-end on the lamp headlamp high-beam circuit and wiggle the harness while measuring — intermittent opens show up as fluctuating readings.
  5. Subsystem check Operate the affected function while watching its switch and motor PIDs in live data.
  6. Subsystem check Inspect connectors and wiring at flex points (door jambs, tailgate hinges) — wires break there first.
  7. Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm B1568 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for B1568 (parts and labor, USD, independent shop rates): Replace the switch or actuator: $120–$450; Repair wiring or connectors: $80–$250; BCM repair or replacement: $300–$900. Overall, fixing B1568 usually costs between $80 and $900. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

What are the symptoms of B1568?

Drivers most often notice: the affected function (locks, windows, lighting, wipers) works intermittently or not at all, warning light on the dashboard, no impact on engine operation in most cases.

Is it safe to drive with B1568?

Usually safe to drive — body codes rarely affect drivability. Exceptions: exterior lighting and wipers in bad weather, and central locking faults that can leave the car unsecured.

What does OBD2 code B1568 mean?

B1568 — Lamp Headlamp High-Beam Circuit Open. A fault in the body electrical system. The car is usually drivable while you plan the repair. Typical causes: body control module (BCM) fault, damaged wiring in door jambs or wet areas, corroded or loose connectors.

How do I diagnose B1568 myself?

Start with a scan: confirm B1568, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the lamp headlamp high-beam, and verify the suspect component against live data before buying parts.

What is the most common cause of B1568?

The most common causes are: body control module (BCM) fault, damaged wiring in door jambs or wet areas, corroded or loose connectors.

Code B1568 points to a fault in the high-beam headlamp circuit — specifically, an open circuit condition. When the body control module or applicable control unit detects that current is not flowing through the high-beam circuit as expected, it logs B1568. The problem sits within the body electrical architecture, not the engine management system itself.

For the circuit to function properly, electricity must travel a complete path: from the fuse, through the headlamp switch, through the wiring harness, and finally to the high-beam bulb assembly. The control module constantly watches for current at the load side of this circuit. When it finds the path broken — a condition known as "open" — it records B1568. This break can happen anywhere along that route: a cut wire, a connector that has worked loose, corrosion eating through terminals, a fuse that has opened, or an internal failure inside the bulb or switch.

The module will not set B1568 after a single bad reading. OBD2 rules require the fault condition to appear consistently or repeat under specific operating parameters before the check engine light (or body control warning) activates. The freeze frame data stored alongside B1568 is valuable — it captures engine load, RPM, coolant temperature, and vehicle speed at the moment the fault was detected. Reproducing those exact conditions during testing gives you the best chance of triggering the problem and confirming the fix.

Common Symptoms of B1568

  • High-beam headlamps fail to illuminate or operate intermittently
  • Affected body functions such as power windows, door locks, or wipers work poorly or not at all
  • Dashboard warning light or indicator related to the high-beam circuit is illuminated
  • High-beam indicator on the instrument cluster does not light up when the lever is activated
  • Related diagnostic trouble codes (often in the B0xxx family) accompany B1568

What Causes B1568?

  • Broken or chafed wire within the high-beam lamp circuit harness
  • Blown fuse providing power to the high-beam circuit
  • Internally failed high-beam lamp assembly
  • Connector unplugged, pins backed out, or significant corrosion on terminals
  • Faulty headlamp switch or related actuator in the affected circuit
  • Loose or corroded electrical connections at harness junctions
  • Wiring damage at flex points such as door jambs or areas exposed to moisture
  • Failed relay feeding the high-beam circuit
  • Faulty body control module (BCM) unable to process the circuit correctly

How to Diagnose B1568

  1. Connect an OBD2 scanner and confirm B1568 is stored. Save the freeze frame data — it tells you the exact conditions present when the fault occurred, which you will need to reproduce during verification.
  2. Look for related trouble codes. Multiple body-system codes appearing together often point to a shared root cause such as a bad ground or a failed module.
  3. Perform a thorough visual inspection of the high-beam circuit wiring and connectors. Look for damaged insulation, broken strands, corrosion buildup, and any signs of water intrusion.
  4. Use a multimeter to check continuity end-to-end on the high-beam circuit. Gently wiggle the harness during testing — intermittent opens will show up as fluctuating or open readings.
  5. Examine connectors and wiring at high-flex areas including door hinges, hood seams, and tailgate areas where wires bend repeatedly.
  6. Operate the high-beam switch while monitoring live data PIDs if your scan tool supports it. Watch for expected values to change or remain stuck.
  7. After repairs are complete, clear B1568 and drive the vehicle through a full drive cycle including the freeze-frame conditions. Confirm the code does not return.

Repair Options for B1568

Target the least expensive and most common failure points before replacing major components:

  • Headlamp switch or actuator replacement — parts and labor: $120–$450
  • Wiring harness repair or connector replacement — parts and labor: $80–$250
  • Body control module (BCM) repair or replacement — parts and labor: $300–$900

How Much Does Fixing B1568 Cost?

The total depends entirely on which component is actually at fault. Based on independent shop labor rates in the United States, the range for B1568-related repairs breaks down as follows: switch or actuator work runs $120–$450, wiring or connector fixes run $80–$250, and BCM replacement or repair runs $300–$900. Most vehicles with B1568 will see a repair bill between $80 and $900. Spending time on accurate diagnosis before purchasing parts is almost always cheaper than replacing the most expensive component first.

Can You Drive with B1568?

Generally yes — body electrical codes like B1568 typically do not affect engine operation or drivability. The primary concern is reduced visibility at night or in poor weather if the high beams fail to work. Secondary concerns include other body systems (wipers, horn, central locking) that may also be affected by the underlying fault. Address the issue before any trip requiring reliable exterior lighting or in conditions where safety systems need to function properly.

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