AutoCodes – Generic – P186F

P186F Code - High Side 3 System Voltage Low Range Out

Quick Answer

The Twin Clutch Sportronic Shift Transmission (TC-SST) Electronic Control Unit (ECU) monitors the system and the voltage of the high side 3 circuit is determined to be too low. Common causes include Faulty Twin Clutch Sportronic Shift Transmission (TC-SST) Electronic Control Unit (ECU), TC-SST-ECU harness is open or shorted, TC-SST-ECU circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P186F indicates High Side 3 System Voltage Low Range Out.
Common causes: Common causes include Faulty Twin Clutch Sportronic Shift Transmission (TC-SST) Electronic Control Unit (ECU), TC-SST-ECU harness is open or shorted, TC-SST-ECU circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 2,594

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jan 31, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P186F Description

The Twin Clutch Sportronic Shift Transmission (TC-SST) Electronic Control Unit (ECU) monitors the system and the voltage of the high side 3 circuit is determined to be too low.

OBDII Code P186F - High Side 3 System Voltage Low Range Out - AutoCodes.com — P186F Code - High Side 3 System Voltage Low Range Out

What does this mean?

What are the Possible Causes of the DTC P186F?

Faulty Twin Clutch Sportronic Shift Transmission (TC-SST) Electronic Control Unit (ECU)
TC-SST-ECU harness is open or shorted
TC-SST-ECU circuit poor electrical connection

How to Fix the DTC P186F?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P186F code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P186F code?

Need more information on how to fix the P186F code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P186F code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P186F Mitsubishi — High Side 3 System Voltage Low Range Out

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P186F Code

1. What does the OBDII code P186F mean?

P186F indicates that the High Side 3 System Voltage is operating below the specified range, typically related to issues in the vehicle's transmission or electrical system.

2. What are the common symptoms of a P186F code?

Symptoms may include erratic shifting, transmission slipping, reduced fuel efficiency, warning lights on the dashboard, or difficulty in engaging certain gears.

3. What causes the P186F code to appear?

Possible causes include a faulty transmission control module (TCM), damaged wiring or connectors, a failing high-side driver circuit, or low system voltage due to battery or alternator issues.

4. Can a weak battery cause the P186F code?

Yes, a weak or failing battery can result in low system voltage, triggering the P186F code.

5. How should I diagnose a P186F code?

Start by checking the battery voltage and alternator output. Inspect the wiring and connectors related to the transmission control module for damage or corrosion. Use a scan tool to monitor TCM data and confirm voltage levels.

6. Is it safe to drive with a P186F code?

Driving with this code may lead to transmission issues or even failure, so itâ€™s recommended to address the problem promptly to avoid further damage.

7. How can I fix the P186F code?

Repairs may include replacing damaged wiring or connectors, reprogramming or replacing the TCM, addressing battery or alternator problems, or repairing the high-side driver circuit.

8. Does the P186F code always require a new TCM?

Not necessarily. The issue could be related to external factors like wiring or voltage supply, so a thorough diagnosis is essential before replacing the TCM.

9. Can a blown fuse cause the P186F code?

Yes, a blown fuse in the circuit supplying power to the TCM or high-side driver can cause this code to appear.

10. Do I need special tools to fix a P186F code?

You may need a multimeter to test voltage, a scan tool to read and clear codes, and potentially a wiring schematic for the vehicle to trace the circuit accurately.