P0285 – OBD-II DTC

OBD-II DTC P0285 – Cylinder 8 Contribution/Balance Fault

DTC P0285 meaning

DTC P0285 refers to a “Cylinder 8 Contribution/Balance Fault.” This diagnostic trouble code indicates that the Engine Control Module (ECM) has detected an imbalance in the performance of cylinder 8 compared to the other cylinders in the engine. This imbalance can be due to various factors affecting the cylinder’s ability to contribute to the engine’s overall performance.

DTC P0285 symptoms

Common symptoms associated with DTC P0285 may include:

• Rough idling or misfiring of the engine
• Decreased engine performance and power
• Increased fuel consumption
• Illuminated check engine light
• Vibration or shaking during acceleration

DTC P0285 causes

Several factors can lead to the triggering of DTC P0285, including:

• Faulty fuel injector for cylinder 8
• Worn or damaged spark plug in cylinder 8
• Vacuum leaks affecting cylinder 8
• Low compression in cylinder 8 due to mechanical issues
• Faulty ignition coil for cylinder 8
• Issues with the engine control module (ECM)

DTC P0285 seriousness

DTC P0285 is considered a serious issue as it indicates that one of the engine’s cylinders is not functioning properly. If left unaddressed, this can lead to:

• Increased emissions
• Potential engine damage
• Decreased fuel efficiency
• Overall poor engine performance

How to diagnose DTC P0285

To diagnose DTC P0285, follow these steps:

1. Use an OBD-II scanner to confirm the presence of DTC P0285.
2. Inspect the engine for any visible signs of damage or wear.
3. Check the fuel injector for cylinder 8 for proper operation.
4. Test the spark plug and ignition coil for cylinder 8.
5. Perform a compression test on cylinder 8 to check for mechanical issues.
6. Look for vacuum leaks around the intake manifold and related components.

How to fix DTC P0285 step-by-step instructions

To fix DTC P0285, follow these steps:

1. Replace the faulty fuel injector for cylinder 8 if necessary.
2. Change the spark plug in cylinder 8 if it is worn or damaged.
3. Replace the ignition coil for cylinder 8 if it is malfunctioning.
4. Repair any vacuum leaks found during diagnosis.
5. Address any mechanical issues identified during the compression test.
6. Clear the DTC using an OBD-II scanner and test drive the vehicle to ensure the issue is resolved.

How to erase DTC P0285

To erase DTC P0285, 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 check if the code returns.

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.