B1574 – OBD-II DTC

OBD-II DTC B1574 – Door Ajar LR Circuit Short To Ground

DTC B1574 meaning

DTC B1574 refers to a diagnostic trouble code indicating a “Door Ajar” condition specifically for the left rear door circuit. This code is triggered when the vehicle’s onboard diagnostic system detects a short to ground in the left rear door ajar circuit. The system monitors the door’s position to ensure it is closed, and a short to ground suggests an electrical fault that may prevent the proper functioning of the door sensor.

DTC B1574 symptoms

Common symptoms associated with DTC B1574 may include:

• Illumination of the warning light on the dashboard indicating a door ajar.
• Inconsistent or false readings from the door ajar indicator.
• Chime or alert sounds when the vehicle is in motion, indicating a door is open.
• Possible issues with the vehicle’s locking system, such as doors not locking or unlocking properly.

DTC B1574 causes

Several factors can lead to the triggering of DTC B1574, including:

• A short circuit in the wiring harness of the left rear door.
• Faulty door ajar switch or sensor.
• Corrosion or damage to electrical connectors related to the door circuit.
• Issues with the vehicle’s body control module (BCM) that processes door status signals.

DTC B1574 seriousness

The seriousness of DTC B1574 can vary. While it may not pose an immediate safety risk, it can lead to:

• Inconvenience due to the constant alert of an open door.
• Potential security issues if the doors do not lock properly.
• Increased wear on the vehicle’s electrical system if the issue is not addressed.

It is advisable to diagnose and repair this code promptly to ensure proper vehicle operation.

How to diagnose DTC B1574

To diagnose DTC B1574, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the B1574 code.
2. Inspect the wiring and connectors of the left rear door for visible damage or corrosion.
3. Test the door ajar switch for proper operation using a multimeter.
4. Check for continuity in the wiring harness to ensure there are no shorts to ground.
5. Examine the body control module for any fault codes or issues that may affect the door circuit.

How to fix DTC B1574 step-by-step instructions

To fix DTC B1574, follow these step-by-step instructions:

1. Disconnect the vehicle’s battery to ensure safety while working on the electrical system.
2. Inspect the wiring harness and connectors for the left rear door. Repair or replace any damaged components.
3. Test the door ajar switch for functionality. Replace it if it is faulty.
4. Check for shorts in the wiring by using a multimeter to measure resistance and continuity.
5. Reconnect the battery and clear the DTC using an OBD-II scanner.
6. Test drive the vehicle to ensure the issue is resolved and the warning light does not reappear.

How to erase DTC B1574

To erase DTC B1574, 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 from the vehicle’s memory.
5. Disconnect the scanner and turn off the ignition.
6. Start the vehicle and monitor for any reoccurrence of the DTC.

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