B1990 – OBD-II DTC

OBD-II DTC B1990 – Pedal Forward / Rearward Potentiometer Feedback Circuit Failure

DTC B1990 meaning

DTC B1990 refers to a fault in the Pedal Forward / Rearward Potentiometer Feedback Circuit. This circuit is responsible for monitoring the position of the accelerator pedal in vehicles equipped with electronic throttle control systems. When the vehicle’s onboard diagnostic system detects an issue with the feedback from this potentiometer, it triggers the B1990 code, indicating a malfunction that could affect vehicle performance and safety.

DTC B1990 symptoms

Common symptoms associated with DTC B1990 may include:

• Illumination of the check engine light
• Unresponsive or erratic throttle response
• Reduced engine power or limp mode activation
• Difficulty in accelerating
• Inconsistent engine performance

DTC B1990 causes

Several factors can lead to the triggering of DTC B1990, including:

• Faulty accelerator pedal position sensor
• Wiring issues such as shorts, opens, or corrosion in the feedback circuit
• Faulty engine control module (ECM)
• Improperly calibrated or malfunctioning throttle body
• Mechanical issues with the accelerator pedal assembly

DTC B1990 seriousness

DTC B1990 is considered a serious issue as it can directly impact the vehicle’s throttle response and overall drivability. If left unaddressed, it may lead to unsafe driving conditions, including sudden loss of power or unintended acceleration. It is advisable to diagnose and repair this code promptly to ensure safe vehicle operation.

How to diagnose DTC B1990

To diagnose DTC B1990, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the B1990 code.
2. Inspect the accelerator pedal position sensor and its wiring for any visible damage or corrosion.
3. Check the electrical connections for secure fit and proper grounding.
4. Test the potentiometer using a multimeter to ensure it is functioning within specifications.
5. Examine the engine control module for any software updates or faults.
6. Clear the code and perform a road test to see if the code returns.

How to fix DTC B1990 step-by-step instructions

To fix DTC B1990, follow these step-by-step instructions:

1. Start by diagnosing the issue as outlined above.
2. If the accelerator pedal position sensor is faulty, replace it with a new one.
3. Repair any damaged wiring or connectors in the feedback circuit.
4. If the ECM is found to be faulty, consider reprogramming or replacing it.
5. Ensure that the throttle body is clean and functioning correctly.
6. After repairs, clear the DTC using an OBD-II scanner.
7. Perform a road test to confirm that the issue has been resolved and the code does not return.

How to erase DTC B1990

To erase DTC B1990, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn the ignition key to the “On” position without starting the engine.
3. Access the diagnostic menu on the scanner and 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 start the vehicle to ensure the code does not reappear.

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