B1974 – OBD-II DTC

OBD-II DTC B1974 – Passenger’s Seat Recline Forward Switch Circuit Short to Battery

DTC B1974 meaning

DTC B1974 refers to a diagnostic trouble code indicating a short circuit in the passenger’s seat recline forward 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 recline forward switch is receiving an unexpected voltage, it triggers this code to alert the technician of a potential electrical issue.

DTC B1974 symptoms

Common symptoms associated with DTC B1974 may include:

• Passenger seat recline function not working
• Warning lights illuminated on the dashboard
• Inconsistent operation of the seat adjustment controls
• Possible malfunction of other related electrical components

DTC B1974 causes

Several factors can lead to the triggering of DTC B1974, including:

• Short circuit in the wiring harness
• Faulty passenger seat recline forward switch
• Corroded or damaged connectors
• Issues with the body control module (BCM)
• Electrical interference from other components

DTC B1974 seriousness

DTC B1974 is considered a moderate to serious issue. While it may not affect the vehicle’s drivability, it can compromise passenger comfort and safety. If the seat cannot be adjusted properly, it may lead to improper seating positions, which can be dangerous in the event of an accident. Therefore, it is advisable to address this code promptly.

How to diagnose DTC B1974

To diagnose DTC B1974, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the B1974 code.
2. Inspect the passenger seat recline forward switch for physical damage.
3. Check the wiring harness and connectors for signs of wear, corrosion, or short circuits.
4. Test the voltage at the switch using a multimeter to ensure it is within specifications.
5. Examine the body control module for any faults or error codes.

How to fix DTC B1974 step-by-step instructions

To fix DTC B1974, follow these steps:

1. Disconnect the vehicle’s battery to ensure safety while working on electrical components.
2. Inspect and repair any damaged wiring or connectors in the passenger seat recline switch circuit.
3. Replace the passenger seat recline forward switch if it is found to be faulty.
4. Reconnect the battery and clear the DTC using an OBD-II scanner.
5. Test the seat recline function to ensure it operates correctly.

How to erase DTC B1974

To erase DTC B1974, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Access the trouble codes menu on the scanner.
3. Select the option to clear or erase trouble codes.
4. Confirm the action and wait for the scanner to complete the process.
5. Disconnect the scanner and take the vehicle for a test drive to ensure the code does not return.

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.