B1989 – OBD-II DTC

OBD-II DTC B1989 – Pedal Position Rearward Switch Circuit Short to Battery

DTC B1989 meaning

DTC B1989 refers to a diagnostic trouble code indicating a short circuit in the pedal position rearward switch circuit to the battery. This code is part of the On-Board Diagnostics II (OBD-II) system, which monitors various vehicle systems for faults. The pedal position rearward switch is responsible for detecting the position of the accelerator pedal, and a short to battery suggests an electrical issue that could affect vehicle performance and safety.

DTC B1989 symptoms

Common symptoms associated with DTC B1989 may include:

• Illumination of the check engine light
• Unresponsive accelerator pedal
• Erratic engine performance
• Reduced power or acceleration
• Potential activation of limp mode

DTC B1989 causes

Several factors can lead to the occurrence of DTC B1989, including:

• Faulty pedal position rearward switch
• Wiring issues, such as frayed or damaged wires
• Corrosion in electrical connectors
• Short circuit in the wiring harness
• Faulty Engine Control Module (ECM)

DTC B1989 seriousness

DTC B1989 is considered a serious issue as it can affect the vehicle’s acceleration and overall performance. If left unaddressed, it may lead to unsafe driving conditions, including loss of power while driving. It is advisable to diagnose and repair this code promptly to ensure vehicle safety and reliability.

How to diagnose DTC B1989

To diagnose DTC B1989, follow these steps:

1. Use an OBD-II scanner to confirm the presence of DTC B1989.
2. Inspect the pedal position rearward switch for any visible damage or wear.
3. Check the wiring and connectors for signs of corrosion or damage.
4. Test the pedal position rearward switch using a multimeter to ensure it operates within specifications.
5. Examine the wiring harness for any shorts to battery voltage.
6. Clear the DTC and perform a road test to see if the code returns.

How to fix DTC B1989 step-by-step instructions

To fix DTC B1989, follow these steps:

1. Disconnect the vehicle’s battery to ensure safety while working on electrical components.
2. Inspect and repair or replace any damaged wiring or connectors related to the pedal position rearward switch.
3. Replace the pedal position rearward switch if it is found to be faulty.
4. Reconnect the battery and clear the DTC using an OBD-II scanner.
5. Perform a road test to verify that the issue has been resolved and that the DTC does not return.

How to erase DTC B1989

To erase DTC B1989, 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 DTC menu on the scanner and select the option to clear or erase codes.
4. Confirm the action and wait for the scanner to complete the process.
5. Disconnect the scanner and perform a test drive to ensure the code does not reappear.

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.