B1799 Code: Meaning, Symptoms, Causes & Fix

B1799

Overview

When B1799 appears, the control module has detected abnormal behavior related to Lamp Turn Signal Front Output Circuit Open in body electronics and comfort modules.

Symptoms

  • battery draw complaints
  • related warning lamp illuminated
  • module resets or glitches

Common causes

  • Disconnected or loose connector affecting lamp turn signal front output circuit open
  • Open circuit in wiring
  • Connector pin damage/corrosion or harness stress near related components

How to diagnose B1799

  1. Confirm B1799 and capture freeze-frame data with a professional scan tool.
  2. Inspect wiring, connectors, and grounds related to lamp turn signal front output circuit open for obvious defects.
  3. Use a continuity test from module pin to component to identify opens/high resistance.
  4. Check for related DTCs to identify the root-cause chain before replacing parts.
  5. After repair, clear codes and confirm readiness monitors complete without recurrence.

Severity of code B1799

Moderate: This code is moderate severity: the vehicle may still operate, but fault progression can increase repair cost over time.

Can you drive with B1799?

Most vehicles can be driven short-term with B1799, but postpone heavy load/highway driving until repaired.

If the warning lamp is flashing or drivability/safety is affected, avoid driving and diagnose immediately.

How to fix it (step-by-step)

  1. Repair obvious wiring/connector faults first to prevent repeat parts replacement.
  2. Address the root fault mode (open) in the lamp turn signal front output circuit open circuit/system.
  3. Apply the required relearn/adaptation procedure if specified by service information.
  4. Road-test and verify B1799 remains cleared under the conditions that originally set the code.

Fix options

  • Clear corrosion and protect terminals.
  • Restore continuity and verify pin tension.
  • Clear DTCs and verify with live data and completed drive cycle.

Typical repair cost

$160-$850

Common mistakes when diagnosing B1799

  • Replacing parts without verifying voltage, ground, and signal integrity first.
  • Ignoring related stored/pending codes that indicate upstream faults.
  • Skipping post-repair verification drive cycle and readiness checks.

B1799 in common vehicles

B1799 appears across makes such as Nissan, Hyundai, Kia, Volkswagen. Failure patterns differ by platform: wiring routes, software calibration, and component supplier revisions can change root cause.

Frequently asked questions

What causes B1799?

B1799 is commonly set by open faults affecting lamp turn signal front output circuit open.

How much does it cost to fix B1799?

For B1799, repair costs are typically $160-$850 depending on exact root cause, labor rates, and part quality.

Can I clear B1799 without repair?

You can clear B1799 temporarily, but the code usually returns until the underlying fault is corrected.

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