B1979 – OBD-II DTC

OBD-II DTC B1979 – Passenger Seat Rearward Switch Circuit Short to Battery

DTC B1979 meaning

DTC B1979 refers to a diagnostic trouble code indicating a short circuit in the passenger seat rearward switch circuit to battery. This code is part of the On-Board Diagnostics II (OBD-II) system, which monitors various vehicle systems for faults. When the system detects that the rearward switch circuit is continuously receiving voltage, it triggers this code, signaling a potential issue with the switch or its wiring.

DTC B1979 symptoms

Common symptoms associated with DTC B1979 may include:

• Passenger seat not moving rearward
• Inoperative seat adjustment controls
• Illuminated warning lights on the dashboard
• Possible malfunction of other seat-related features

DTC B1979 causes

Several factors can lead to the triggering of DTC B1979, including:

• Faulty rearward switch
• Damaged or frayed wiring in the seat adjustment circuit
• Corrosion or poor connections in the electrical connectors
• Short circuit to battery voltage due to insulation failure
• Malfunctioning seat control module

DTC B1979 seriousness

DTC B1979 is considered a moderate issue. While it may not affect the vehicle’s overall drivability, it can compromise passenger comfort and safety. The inability to adjust the seat properly can lead to improper seating positions, which may affect airbag deployment and overall safety in the event of a collision. It is advisable to address this code promptly.

How to diagnose DTC B1979

To diagnose DTC B1979, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the B1979 code.
2. Inspect the passenger seat rearward switch for physical damage or wear.
3. Check the wiring and connectors for signs of corrosion, fraying, or disconnection.
4. Test the rearward switch using a multimeter to ensure it operates correctly.
5. Examine the seat control module for any faults or error codes.
6. Perform a continuity test on the wiring harness to check for shorts to battery voltage.

How to fix DTC B1979 step-by-step instructions

To fix DTC B1979, follow these steps:

1. Disconnect the vehicle’s battery to ensure safety while working on electrical components.
2. Remove the passenger seat to access the wiring and switch.
3. Inspect and repair or replace any damaged wiring or connectors.
4. Replace the faulty rearward switch if it is not functioning correctly.
5. Reconnect all electrical connections and ensure they are secure.
6. Reinstall the passenger seat and reconnect the battery.
7. Clear the DTC using an OBD-II scanner and test the seat adjustment functionality.

How to erase DTC B1979

To erase DTC B1979, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the vehicle’s 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 start the vehicle to ensure the code does not reappear.

Recommended tools for OBD-II diagnostics

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