P1621 – OBD-II DTC

OBD-II DTC P1621 – SBDS Interactive Codes

DTC P1621 meaning

DTC P1621 refers to a diagnostic trouble code that indicates a problem with the SBDS (Smart Body Control Module) communication. This code is often associated with issues in the vehicle’s body control module, which manages various electronic functions within the vehicle. The code suggests that there is a malfunction in the communication between the engine control module (ECM) and the body control module.

DTC P1621 symptoms

Common symptoms associated with DTC P1621 may include:

• Illumination of the check engine light
• Malfunctioning of electrical components (e.g., lights, windows)
• Inconsistent operation of the vehicle’s electronic systems
• Difficulty in starting the vehicle
• Loss of certain features (e.g., remote keyless entry)

DTC P1621 causes

Several potential causes for DTC P1621 include:

• Faulty body control module
• Wiring issues or damaged connectors
• Corrosion in electrical connections
• Software glitches in the control modules
• Faulty engine control module

DTC P1621 seriousness

The seriousness of DTC P1621 can vary. While it may not immediately affect the drivability of the vehicle, it can lead to further electrical issues if not addressed. Ignoring this code may result in malfunctioning electronic systems, which can compromise safety and convenience features.

How to diagnose DTC P1621

To diagnose DTC P1621, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the P1621 code.
2. Check for any additional trouble codes that may provide more context.
3. Inspect the wiring and connectors related to the body control module and engine control module.
4. Test the body control module for proper operation.
5. Check for software updates or reprogramming needs for the control modules.

How to fix DTC P1621 step-by-step instructions

To fix DTC P1621, follow these steps:

1. Clear the DTC using an OBD-II scanner.
2. Inspect and repair any damaged wiring or connectors.
3. Replace the body control module if it is found to be faulty.
4. Reprogram or update the software of the control modules if necessary.
5. Test the vehicle to ensure that the issue is resolved and the code does not return.

How to erase DTC P1621

To erase DTC P1621, 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 option to clear or erase trouble codes on the scanner.
4. Confirm the action to erase the codes.
5. Disconnect the scanner and start the vehicle to check if the code reappears.

Recommended tools for OBD-II diagnostics

Explore our expert picks: The Best OBD2 Scanners for 2025

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.