AutoCodes – Lexus – P1520 Lexus

P1520 Lexus Code - Stop Lamp Switch Malfunction

Quick Answer

This signal is used to detect when the brakes have been applied. Common causes include Faulty Stop Light Switch, Stop Light Switch harness is open or shorted, Stop Light Switch 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: P1520 Lexus indicates Stop Lamp Switch Malfunction.
Common causes: Common causes include Faulty Stop Light Switch, Stop Light Switch harness is open or shorted, Stop Light Switch 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 11,375

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Aug 27, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1520 Lexus Description

This signal is used to detect when the brakes have been applied. The STP signal voltage is the same as the voltage supplied to the stop lights. The STP signal is used mainly to control the fuel cut–off engine speed (The fuel cut–off engine speed is reduced slightly when the vehicle is braking).

OBDII Code P1520 Lexus - Stop Lamp Switch Malfunction - AutoCodes.com — P1520 Lexus Code - Stop Lamp Switch Malfunction

What does this mean?

What are the Possible Causes of the DTC P1520 Lexus?

Faulty Stop Light Switch
Stop Light Switch harness is open or shorted
Stop Light Switch circuit poor electrical connection
Faulty Engine Control Module (ECM)

How to Fix the DTC P1520 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 P1520 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 P1520 Lexus Code

1. What does the OBDII code P1520 mean on a Lexus?

P1520 indicates a Stop Lamp Switch Malfunction, meaning the vehicle's ECM has detected an issue with the brake light switch or its circuit.

2. What are the common symptoms of the P1520 code in a Lexus?

Symptoms may include the brake lights not working, the vehicle being stuck in park, the check engine light turning on, or issues with cruise control functionality.

3. What causes the P1520 code to appear on a Lexus?

It is usually caused by a faulty stop lamp switch, damaged wiring or connectors, a blown fuse, or improper adjustment of the brake light switch.

4. Can I drive my Lexus with a P1520 code?

Driving with a P1520 code can be unsafe if the brake lights are not functioning properly, as this can make it harder for other drivers to see when you're braking.

5. How can I diagnose the P1520 code on my Lexus?

Start by checking the brake lights for proper operation, inspecting the stop lamp switch and its wiring for damage or disconnection, and testing the switch with a multimeter.

6. How do I fix the P1520 code on a Lexus?

Repair or replace the stop lamp switch if faulty, fix any damaged wiring or connectors, and ensure the switch is properly adjusted to the brake pedal.

7. How much does it cost to repair a P1520 code on a Lexus?

Repair costs can vary, but replacing a stop lamp switch typically costs $50â€“$150 for parts and labor, depending on the vehicle model and labor rates.

8. Can a faulty stop lamp switch affect other systems in my Lexus?

Yes, a faulty stop lamp switch can impact systems like cruise control, traction control, and the shift interlock mechanism, preventing the vehicle from shifting out of park.

9. How do I reset the P1520 code after repairs?

After repairs, the code can be cleared using an OBDII scanner. If the issue is resolved, the code should not return.

10. What tools do I need to fix a P1520 code on my Lexus?

You may need an OBDII scanner, a multimeter, basic hand tools, and possibly a service manual for your specific Lexus model to diagnose and fix the issue.