B1588 – Autolamp Delay Increase Circuit Open

The ODBII code B1588 indicates a malfunction in the autolamp delay increase circuit, specifically that the circuit is open, meaning there is a break in the electrical connection preventing proper function.

The severity of ODBII code B1588 is generally considered moderate.

Common Causes For: B1587 Autolamp Delay Increase Circuit Failure

• Open circuit in the autolamp delay wiring
• Faulty autolamp delay relay
• Defective body control module (BCM)
• Poor ground connection
• Damaged or corroded connectors
• Faulty headlight switch
• Short circuit in the wiring harness

Common misdiagnosis for B1588 Autolamp Delay Increase Circuit Open

• Faulty headlight switch
• Defective body control module (BCM)
• Wiring issues or shorts in the circuit
• Malfunctioning autolamp sensor
• Incorrectly diagnosed battery or charging system problems
• Issues with the vehicle’s lighting system or bulbs
• Faulty relay or fuse related to the autolamp system

Common Troubleshooting Steps

The OBD-II code B1588 refers to an issue with the autolamp delay increase circuit, indicating that there is an open circuit in the system responsible for controlling the delay of the autolamps (automatic headlights). Here are some common troubleshooting steps to diagnose and resolve this issue:

• Check the Vehicle’s Manual: Refer to the vehicle’s service manual for specific information about the autolamp system and wiring diagrams.
• Visual Inspection: Inspect the wiring and connectors associated with the autolamp delay circuit for any signs of damage, corrosion, or loose connections.
• Look for frayed wires, broken connectors, or any other physical damage.
• Check Fuses: Locate and check the fuses related to the autolamp system. A blown fuse can cause the circuit to open.
• Replace any blown fuses and retest the system.
• Test the Autolamp Switch: Test the autolamp switch for proper operation. Ensure that it is functioning correctly and making good contact.
• If the switch is faulty, replace it.
• Inspect the Control Module: Check the body control module (BCM) or any other relevant control modules for faults. Use a scan tool to check for additional codes that may indicate a problem with the module.
• If the module is faulty, it may need to be reprogrammed or replaced.
• Check for Short Circuits: Use a multimeter to check for continuity in the wiring. Look for any short circuits that may be affecting the autolamp delay circuit.
• Repair any shorts found in the wiring.
• Test the Autolamp Delay Circuit: Use a multimeter to test the resistance and voltage in the autolamp delay circuit. Compare the readings to the specifications in the service manual.
• If the readings are outside the specified range, further investigation into the circuit may be necessary.
• Clear Codes and Retest: After performing repairs, clear the OBD-II codes using a scan tool and take the vehicle for a test drive to see if the code returns.
• Monitor the autolamp system to ensure it is functioning correctly.
• Seek Professional Help: If the issue persists after performing the above steps, consider seeking help from a professional mechanic or automotive technician who has experience with electrical systems. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the B1588 OBD-II code.