AutoCodes – Lexus – P109D Lexus

P109D Lexus Code - Short in Fuel Pressure Switching Valve Circuit

Quick Answer

A Flexible Fuel Vehicle (FFV) can be used with a fuel containing a high concentration of ethyl alcohol. Common causes include Faulty Fuel Pressure Switching Valve, Fuel Pressure Switching Valve harness is open or shorted, Fuel Pressure Switching Valve 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: P109D Lexus indicates Short in Fuel Pressure Switching Valve Circuit.
Common causes: Common causes include Faulty Fuel Pressure Switching Valve, Fuel Pressure Switching Valve harness is open or shorted, Fuel Pressure Switching Valve 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.

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Code Popularity 1,265

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 Jun 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P109D Lexus Description

A Flexible Fuel Vehicle (FFV) can be used with a fuel containing a high concentration of ethyl alcohol.
This FFV uses a fuel pressure switching system which changes the fuel pressure to low or high using a fuel pressure switching valve.
The code is stored when a malfunction is detected in the fuel pressure switching valve circuit. If the voltage of the fuel pressure switching valve circuit is different from the voltage commanded by the Engine Control Module (ECM), the ECM determines that the fuel pressure switching valve circuit is open or shorted, and stores a DTC.

OBDII Code P109D Lexus - Short in Fuel Pressure Switching Valve Circuit - AutoCodes.com — P109D Lexus Code - Short in Fuel Pressure Switching Valve Circuit

What does this mean?

What are the Possible Causes of the DTC P109D Lexus?

Faulty Fuel Pressure Switching Valve
Fuel Pressure Switching Valve harness is open or shorted
Fuel Pressure Switching Valve circuit poor electrical connection
Faulty F/PMP VSV relay
Faulty Engine Control Module (ECM)

How to Fix the DTC P109D Lexus?

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 P109D Lexus 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.

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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 P109D Lexus Code

1. What are the common symptoms of OBDII code P109D in a Lexus related to a short in the Fuel Pressure Switching Valve Circuit?

The common symptoms include rough idling, decreased fuel efficiency, and potentially stalling of the engine.

2. What are the possible causes of OBDII code P109D in a Lexus?

Common causes may include a faulty fuel pressure switching valve, damaged wiring or connectors in the circuit, or a problem with the engine control module (ECM).

3. How can I diagnose the issue related to OBDII code P109D in my Lexus?

You can start by checking the wiring and connectors for any visible damage, testing the fuel pressure switching valve for proper functionality, and using a scan tool to monitor the sensor readings.

4. What are the repair options for fixing OBDII code P109D in a Lexus?

Repair options may include replacing the faulty fuel pressure switching valve, repairing damaged wiring or connectors, or reprogramming the engine control module if needed.

5. Can I drive my Lexus with an active OBDII code P109D?

It is not recommended to drive the vehicle with an active fault code, as it can potentially lead to more serious issues and engine damage if left unresolved.

6. Will resetting the fault code make OBDII code P109D go away permanently?

Resetting the fault code may temporarily clear the error code, but if the underlying issue causing the code is not fixed, it is likely to reappear upon driving the vehicle again.

7. How much does it typically cost to repair OBDII code P109D in a Lexus?

The cost of repair can vary depending on the specific cause of the issue, but it may range from a few hundred to a thousand dollars, including parts and labor.

8. Is it possible to prevent OBDII code P109D from occurring in the future?

Regular maintenance of the fuel system and electrical components, as well as addressing any warning signs promptly, can help prevent issues leading to this fault code.

9. Can a DIY enthusiast fix OBDII code P109D in a Lexus?

Depending on the individual's skill level and access to tools, some DIY enthusiasts may be able to diagnose and repair the issue themselves, but it is recommended to consult a professional if unsure.

10. How long does it typically take to repair OBDII code P109D in a Lexus?

The repair time can vary based on the complexity of the issue and the availability of parts, but it may take a few hours to a full day for a professional technician to diagnose and fix the problem.