B1566 – OBD-II DTC

OBD-II DTC B1566 – Door Ajar Circuit Short To Ground

DTC B1566 meaning

DTC B1566 refers to a diagnostic trouble code indicating a fault in the door ajar circuit, specifically a short to ground condition. This code is triggered when the vehicle’s onboard diagnostic system detects that the door ajar switch is continuously signaling that a door is open, even when it is closed. This can lead to issues with the vehicle’s interior lights, alarm system, and other related functions.

DTC B1566 symptoms

Common symptoms associated with DTC B1566 may include:

• Interior lights remaining on when doors are closed
• Door ajar warning light illuminated on the dashboard
• Alarm system malfunctioning or false alarms
• Inconsistent operation of power door locks

DTC B1566 causes

Several factors can lead to the triggering of DTC B1566, including:

• Faulty door ajar switch
• Wiring issues, such as frayed or damaged wires
• Corrosion in the door harness connectors
• Short circuit in the door ajar circuit
• Faulty body control module (BCM)

DTC B1566 seriousness

The seriousness of DTC B1566 can vary depending on the symptoms experienced. While it may not immediately affect the drivability of the vehicle, it can lead to:

• Increased battery drain due to interior lights staying on
• Potential safety issues if the alarm system fails
• Inconvenience from malfunctioning door locks

It is advisable to address this code promptly to avoid further complications.

How to diagnose DTC B1566

To diagnose DTC B1566, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the B1566 code.
2. Inspect the door ajar switch for proper operation.
3. Check the wiring and connectors for signs of damage or corrosion.
4. Test the continuity of the door ajar circuit.
5. Examine the body control module for faults.

How to fix DTC B1566 step-by-step instructions

To fix DTC B1566, follow these step-by-step instructions:

1. Disconnect the vehicle’s battery to ensure safety.
2. Inspect and replace the door ajar switch if it is faulty.
3. Repair or replace any damaged wiring or connectors in the door harness.
4. Test the door ajar circuit for proper voltage and continuity.
5. If necessary, reprogram or replace the body control module.
6. Reconnect the battery and clear the DTC using an OBD-II scanner.

How to erase DTC B1566

To erase DTC B1566, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the ignition without starting the engine.
3. Navigate to the “Erase Codes” or “Clear DTCs” option on the scanner.
4. Confirm the action to clear the trouble codes.
5. Disconnect the scanner and start the vehicle to ensure the code does not return.