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Engine-Codes – Generic – B1391

B1391 Code - Oil Level Switch Circuit Failure

Quick Answer

The B1391 diagnostic trouble code (DTC) indicates a failure in the oil level switch circuit. Common causes include Faulty oil level switch, Damaged wiring or connectors in the oil level switch circuit, Corrosion or contamination in the oil level switch components. 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
B1391 indicates Oil Level Switch Circuit Failure.
Common causes
Common causes include Faulty oil level switch, Damaged wiring or connectors in the oil level switch circuit, Corrosion or contamination in the oil level switch components.
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.
What is this?
Table of contents Created and updated by William Orellana on Sep 09, 2024
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Code B1391 Description

The B1391 diagnostic trouble code (DTC) indicates a failure in the oil level switch circuit. This switch is responsible for monitoring the oil level in the engine and sending this information to the vehicle's computer system. The oil level switch is crucial for ensuring that the engine has enough oil for proper lubrication and cooling. When the switch circuit fails, it can lead to inaccurate oil level readings, potentially causing damage to the engine if the oil level is too low.

OBDII Code B1391 - Oil Level Switch Circuit Failure
B1391 Code - Oil Level Switch Circuit Failure

Common Causes of B1391

  1. Faulty oil level switch.
  2. Damaged wiring or connectors in the oil level switch circuit.
  3. Corrosion or contamination in the oil level switch components.
  4. Issues with the vehicle's computer system receiving and interpreting oil level data.
  5. Low oil level or oil leakage affecting the oil level switch operation.

Symptoms of B1391

  1. Illumination of the oil pressure warning light on the dashboard.
  2. Check engine light being triggered.
  3. Inaccurate oil level readings on the dashboard display.
  4. Engine running rough or stalling unexpectedly.
  5. Reduced engine performance or fuel efficiency.

How to Fix B1391

  1. Begin by conducting a visual inspection of the oil level switch and its wiring for any visible damage or corrosion.
  2. Test the oil level switch using a multimeter to determine if it is functioning correctly.
  3. Check the wiring and connectors for continuity and repair or replace any damaged components.
  4. Clear the DTC from the vehicle's computer system using a diagnostic scanner.
  5. Test drive the vehicle to ensure that the issue has been resolved and that the warning lights do not reappear.

Cost to Fix B1391

The typical repair costs for addressing an oil level switch circuit failure can vary depending on the extent of the issue and the specific components that need to be replaced. Generally, the parts required for this repair, such as the oil level switch or wiring harness, can cost between $50 and $200. Labor costs at auto repair shops can range from $100 to $300, with total repair costs typically falling between $150 and $500. It is essential to keep in mind that these estimates are approximate and that actual costs may vary based on factors such as location, vehicle make and model, and labor rates at the chosen repair facility. It is recommended to consult with a professional technician for a more accurate cost estimate tailored to your specific situation.

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Code B1391 Information for Specific Makes

  • B1391 Hyundai — Passenger Seat Track Position Sensor Short Or Short To Battery
  • B1391 KIA — Passenger Seat Track Position Sensor Short Or Short To Battery
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 B1391 Code

1. What are the common symptoms of OBDII code B1391 (Oil Level Switch Circuit Failure)?

- Common symptoms include an illuminated oil pressure warning light on the dashboard, inaccurate oil level readings, or no oil level reading at all.

2. What are some possible causes of OBDII code B1391?

- The code B1391 can be triggered by a faulty oil level switch, damaged wiring or connectors in the oil level switch circuit, or low engine oil level.

3. How can I diagnose the cause of OBDII code B1391?

- To diagnose the issue, you can start by visually inspecting the oil level switch and its wiring for any signs of damage. You can also use a multimeter to test the continuity of the circuit.

4. Can driving with OBDII code B1391 cause any serious damage to my vehicle?

- Driving with code B1391 may lead to inaccurate oil level readings, which can potentially cause engine damage due to insufficient lubrication. It is recommended to address the issue promptly.

5. What are some repair tips for fixing OBDII code B1391?

- Repair options include replacing the faulty oil level switch, repairing damaged wiring or connectors, and ensuring the engine oil level is at the appropriate level. Clearing the code with an OBDII scanner is also recommended after repairs.

6. Is it safe to continue driving my vehicle with OBDII code B1391 unresolved?

- It is not recommended to drive the vehicle with code B1391 unresolved, as it can lead to potential engine damage or inaccurate oil level readings. It's best to address the issue as soon as possible.

7. How much does it typically cost to repair OBDII code B1391?

- The cost of repairing code B1391 can vary depending on the cause of the issue and the labor rates of the repair shop. In general, the cost may range from $100 to $300, including parts and labor.

8. Can I reset OBDII code B1391 without fixing the underlying issue?

- While you can clear the code temporarily with an OBDII scanner, it is important to address the root cause of the issue to prevent further problems with the oil level monitoring system.

9. Are there any preventive maintenance steps to avoid OBDII code B1391 in the future?

- Regularly checking and maintaining the engine oil level, as well as inspecting the oil level switch and its wiring during routine maintenance, can help prevent issues that trigger code B1391.

10. How long does it typically take to repair OBDII code B1391?

- The repair time for code B1391 can vary based on the specific cause of the issue and the expertise of the technician. In general, it may take 1-2 hours to diagnose and repair the problem.

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