B1284 – OBD-II DTC

OBD-II DTC B1284 – Servo Motor Potentiometer Airintake Left Circuit Failure

DTC B1284 meaning

DTC B1284 refers to a diagnostic trouble code indicating a failure in the servo motor potentiometer circuit for the left air intake. This code is part of the On-Board Diagnostics II (OBD-II) system, which monitors various vehicle components to ensure proper operation. The servo motor is responsible for adjusting the position of the air intake, and the potentiometer provides feedback on its position. A failure in this circuit can lead to improper air intake adjustments, affecting engine performance and emissions.

DTC B1284 symptoms

Common symptoms associated with DTC B1284 may include:

• Check Engine Light illuminated
• Reduced engine performance
• Increased fuel consumption
• Unusual engine noises
• Difficulty in starting the engine

DTC B1284 causes

Several factors can lead to the occurrence of DTC B1284, including:

• Faulty servo motor
• Damaged or corroded wiring in the potentiometer circuit
• Defective potentiometer
• Poor electrical connections
• Malfunctioning engine control module (ECM)

DTC B1284 seriousness

DTC B1284 is considered a moderate to serious issue. While it may not cause immediate engine failure, it can lead to significant performance issues and increased emissions. Ignoring this code can result in further damage to the engine or related components, potentially leading to costly repairs. It is advisable to address this code promptly to maintain optimal vehicle performance.

How to diagnose DTC B1284

To diagnose DTC B1284, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the DTC.
2. Inspect the wiring and connectors related to the servo motor and potentiometer for damage or corrosion.
3. Check the functionality of the servo motor by testing its operation.
4. Test the potentiometer for proper resistance values using a multimeter.
5. Examine the engine control module (ECM) for any faults or updates.

How to fix DTC B1284 step-by-step instructions

To fix DTC B1284, follow these step-by-step instructions:

1. Disconnect the battery to ensure safety while working on the electrical components.
2. Inspect and repair any damaged wiring or connectors in the potentiometer circuit.
3. If the servo motor is faulty, replace it with a new one.
4. Replace the potentiometer if it is found to be defective.
5. Reconnect the battery and clear the DTC using an OBD-II scanner.
6. Test drive the vehicle to ensure the issue is resolved and the Check Engine Light does not reappear.

How to erase DTC B1284

To erase DTC B1284, 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 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 start the engine to verify that the Check Engine Light is off.

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.