P1486 – OBD-II DTC

OBD-II DTC P1486 – Fan Secondary Low With High Fan On

DTC P1486 meaning

DTC P1486 refers to a diagnostic trouble code indicating a problem with the secondary fan system in a vehicle. Specifically, it signifies that the secondary fan is operating at a low speed while the primary fan is running at a high speed. This discrepancy can lead to inadequate cooling of the engine, potentially causing overheating and other related issues.

DTC P1486 symptoms

Common symptoms associated with DTC P1486 may include:

• Engine overheating
• Increased engine temperature gauge readings
• Unusual noises from the cooling fan
• Check Engine Light illuminated
• Reduced engine performance

DTC P1486 causes

Several factors can contribute to the occurrence of DTC P1486, including:

• Faulty secondary cooling fan
• Wiring issues or damaged connectors
• Malfunctioning fan relay
• Faulty engine control module (ECM)
• Cooling system blockages or leaks

DTC P1486 seriousness

DTC P1486 is considered a serious issue as it can lead to engine overheating. If not addressed promptly, this can result in severe engine damage, including warped cylinder heads or blown head gaskets. It is essential to diagnose and repair the underlying problem to prevent further complications.

How to diagnose DTC P1486

To diagnose DTC P1486, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the P1486 code.
2. Inspect the secondary fan and its wiring for any visible damage or disconnections.
3. Test the fan relay for proper operation.
4. Check the voltage and ground at the fan connector.
5. Examine the engine control module (ECM) for any faults or updates.
6. Perform a cooling system inspection for blockages or leaks.

How to fix DTC P1486 step-by-step instructions

To fix DTC P1486, follow these step-by-step instructions:

1. Confirm the DTC P1486 code using an OBD-II scanner.
2. Inspect the secondary fan for any physical damage or obstructions.
3. Check the wiring and connectors for signs of wear or corrosion.
4. Test the fan relay by swapping it with a known good relay.
5. Measure voltage at the fan connector while the engine is running to ensure proper power supply.
6. If the fan is faulty, replace it with a new unit.
7. Clear the DTC using the OBD-II scanner and test drive the vehicle to ensure the issue is resolved.

How to erase DTC P1486

To erase DTC P1486, 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 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.