The OBD-II trouble code B1690 – Autolamp Delay Circuit Open – indicates an issue within your vehicle’s autolamp system, specifically pointing to a problem with the delay circuit that controls the automatic headlights. This system is designed to enhance safety and convenience by automatically turning your headlights on or off based on ambient lighting conditions. When this code appears, it means the control module has detected an open circuit or interruption in the delay function, potentially causing your autolamps to malfunction or fail to operate as intended. Keep scrolling to discover practical guidance on how to identify this fault, understand its common causes, and learn effective steps to fix the problem and get your autolamps working smoothly again.

What symptoms might indicate the B1690 error?

When this issue arises, drivers may notice several distinct symptoms affecting their vehicle’s lighting system. Understanding these signs can help identify the problem early and ensure safety on the road.

  • 1. Delayed headlight activation: Headlights turn on slower than usual after using the switch
  • 2. Headlights remain on: Lights stay illuminated longer than expected when the vehicle is turned off
  • 3. Inconsistent lighting behavior: Headlights flicker or behave unpredictably during operation
  • 4. Warning indicator on dashboard: A light symbol or alert appears indicating a lighting system fault
  • 5. Reduced automatic light function: Automatic headlights fail to operate correctly or respond late

      • Common reasons that can lead to error code B1690

      • 1. Faulty Wiring Harness: Damaged or corroded wiring can interrupt the circuit connection causing malfunction.
      • 2. Defective Delay Relay: A malfunctioning relay can fail to maintain the necessary delay in the circuit.
      • 3. Blown Fuse: A blown fuse can break the electrical continuity required for proper operation.
      • 4. Poor Ground Connection: Inadequate grounding can lead to intermittent or complete circuit failure.
      • 5. Malfunctioning Control Module: The control unit responsible for timing may have internal faults affecting the circuit.

      B1690 at-home error code check step by step

      When diagnosing automotive issues at home, having a clear, step-by-step approach can save both time and money. Here’s how you can check if the B1690 – Autolamp Delay Circuit Open is faulty using your own tools, including an OBD-II scanner.

      First, connect your OBD-II reader to the vehicle’s diagnostic port, usually located under the dashboard. Turn the ignition to the ON position without starting the engine and use the scanner to read live data related to the autolamp system. Next, observe whether the autolamp delay function is active and if there are any irregularities or absence of expected signals during turning off the lights. Then, perform a visual inspection of the wiring harness and connectors associated with the autolamp delay circuit for signs of damage or corrosion. Lastly, use a multimeter to measure continuity across the circuit; an open circuit reading indicates a fault consistent with this code.

      B1690 error repair at home: What can you do yourself and when do you need a mechanic?

      This issue typically affects the automatic headlight delay function and may indicate a problem within the vehicle’s lighting system. Performing some basic checks at home can help identify or resolve common causes before seeking professional help.

      • 1. Fuse Inspection: Check and replace any blown fuses related to the lighting circuit to ensure power is reaching the system properly.
      • 2. Wiring Connection Check: Inspect wiring harnesses and connectors for corrosion, damage, or loose connections around the headlamp delay module and related components.
      • 3. Battery Voltage Test: Verify that the vehicle’s battery voltage is stable and sufficient, as low voltage can cause circuit malfunctions.
      • 4. Relay Function Test: Swap or test the relevant relays controlling the headlamp delay to rule out relay failure.

      If these steps do not resolve the problem, or if you encounter complex wiring issues or module faults, it is advisable to consult a professional technician for accurate diagnosis and repair.

      Consequences of error B1690 if you don’t fix it in time

      Ignoring this issue can lead to several serious long-term consequences affecting vehicle performance and safety. Addressing it promptly is crucial to avoid further damage.

      • 1. Electrical System Failure: Prolonged neglect may cause damage to related electrical components, leading to widespread failures in the vehicle’s lighting system.
      • 2. Reduced Visibility: Malfunctioning lighting delays can result in improper headlight operation, increasing the risk of accidents during low-light conditions.
      • 3. Battery Drain: Continuous circuit faults can cause excessive current draw, ultimately draining the battery and leaving the vehicle inoperable.
      • 4. Increased Repair Costs: Delaying repairs may exacerbate the problem, resulting in more extensive and expensive repairs down the line.
      • 5. Safety System Compromise: Faulty lighting circuits can interfere with other safety features relying on proper illumination, reducing overall vehicle safety.

          • Here’s how to prevent the B1690 error with a few simple steps

          The B1690 – Autolamp Delay Circuit Open error can often be prevented with consistent maintenance and careful handling of the vehicle’s electrical components. Implementing these practical tips will help you avoid encountering this issue.