P1284 – OBD-II DTC

OBD-II DTC P1284 – Cylinder #8 High To Low Side Open

DTC P1284 meaning

DTC P1284 refers to a diagnostic trouble code indicating a high to low side open circuit condition in the cylinder #8 fuel injector. This code is part of the On-Board Diagnostics II (OBD-II) system, which monitors various components of the vehicle’s engine and emissions systems. When the Engine Control Module (ECM) detects that the voltage signal from the injector is not within the expected range, it triggers this code.

DTC P1284 symptoms

Common symptoms associated with DTC P1284 may include:

• Engine misfires or rough idling
• Decreased engine performance
• Increased fuel consumption
• Check Engine Light illuminated
• Potential stalling or difficulty starting the engine

DTC P1284 causes

Several factors can lead to the triggering of DTC P1284, including:

• Faulty fuel injector for cylinder #8
• Wiring issues, such as damaged or corroded connectors
• Open circuit in the injector harness
• Faulty Engine Control Module (ECM)
• Issues with the fuel delivery system

DTC P1284 seriousness

DTC P1284 is considered a moderate to serious issue. While it may not cause immediate catastrophic failure, it can lead to poor engine performance, increased emissions, and potential damage to other engine components if not addressed promptly. It is advisable to diagnose and repair the issue to maintain optimal vehicle performance and reliability.

How to diagnose DTC P1284

To diagnose DTC P1284, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the P1284 code.
2. Inspect the wiring and connectors for cylinder #8 injector for any visible damage or corrosion.
3. Check the resistance of the injector using a multimeter to ensure it is within specifications.
4. Test the voltage supply to the injector while the engine is running.
5. Examine the ECM for any faults or updates that may affect injector operation.

How to fix DTC P1284 step-by-step instructions

To fix DTC P1284, follow these steps:

1. Repair or replace any damaged wiring or connectors related to the cylinder #8 injector.
2. If the injector is faulty, replace it with a new or refurbished unit.
3. Ensure all connections are secure and free from corrosion.
4. Clear the DTC using an OBD-II scanner.
5. Test drive the vehicle to ensure the code does not reappear and that engine performance is restored.

How to erase DTC P1284

To erase DTC P1284, 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 “Erase Codes” or “Clear DTCs” option on the scanner.
4. Confirm the action to clear the trouble codes.
5. Disconnect the scanner and start the engine to verify that 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.