AutoCodes – GMC – P1574 GMC

P1574 GMC Code - Stop Lamp Switch Circuit

Quick Answer

This diagnostic test functions on the assumption that a sudden decrease in vehicle speed is caused by a brake pedal application. Common causes include Stop Lamp Switch out of adjustment, Faulty Stop Lamp Switch, Stop Lamp Switch harness is open or shorted. 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: P1574 GMC indicates Stop Lamp Switch Circuit.
Common causes: Common causes include Stop Lamp Switch out of adjustment, Faulty Stop Lamp Switch, Stop Lamp Switch harness is open or shorted.
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 12,825

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 May 18, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1574 GMC Description

This diagnostic test functions on the assumption that a sudden decrease in vehicle speed is caused by a brake pedal application. When the Powertrain Control Module (PCM) detects that there is a 4.2 km/h (2.6 mph) or greater decrease in vehicle speed within 0.25 seconds and a transition of the Torque Converter Clutch (TCC) brake/cruise release switch without a transition of the stop lamp switch, the PCM sets DTC P1574.

OBDII Code P1574 GMC - Stop Lamp Switch Circuit - AutoCodes.com — P1574 GMC Code - Stop Lamp Switch Circuit

What does this mean?

What are the Possible Causes of the DTC P1574 GMC?

Stop Lamp Switch out of adjustment
Faulty Stop Lamp Switch
Stop Lamp Switch harness is open or shorted
Stop Lamp Switch circuit poor electrical connection

How to Fix the DTC P1574 GMC?

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 P1574 GMC 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 P1574 GMC code?

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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 P1574 GMC Code

1. What are common symptoms of OBDII code P1574 GMC (Stop Lamp Switch Circuit)?

Common symptoms include the brake lights staying on or not working properly, the cruise control not engaging, and the inability to shift out of park.

2. What are possible causes of OBDII code P1574 GMC?

Possible causes include a faulty stop lamp switch, a problem with the brake pedal position sensor, a wiring issue in the circuit, or a malfunction in the vehicle's computer system.

3. How can I diagnose the cause of OBDII code P1574 GMC?

You can diagnose the issue by checking the stop lamp switch for proper operation, inspecting the brake pedal position sensor, examining the wiring for any damage, and using an OBDII scanner to read the trouble codes.

4. Can I still drive my vehicle with OBDII code P1574 GMC?

It is not recommended to drive your vehicle with this code as it can affect the proper functioning of your brake lights and potentially lead to unsafe driving conditions.

5. How can I repair OBDII code P1574 GMC?

To repair this code, you may need to replace the stop lamp switch, repair any damaged wiring, or recalibrate the brake pedal position sensor. It is advisable to seek professional help for accurate diagnosis and repair.

6. Will OBDII code P1574 GMC cause my vehicle to fail an emissions test?

While this code is related to the stop lamp switch circuit and not directly related to emissions, it is still important to address and repair the issue to ensure the overall health and safety of your vehicle.

7. Is OBDII code P1574 GMC a common issue in GMC vehicles?

Yes, this code can be a common issue in GMC vehicles, particularly in models with electronic brake systems and cruise control features.

8. Can a DIY enthusiast fix OBDII code P1574 GMC at home?

Some basic repairs related to this code, such as replacing the stop lamp switch, can be done at home by DIY enthusiasts with the necessary tools and knowledge. However, more complex issues may require professional assistance.

9. How much does it cost to repair OBDII code P1574 GMC at a mechanic?

The cost of repairing this code can vary depending on the specific cause of the issue, the labor rates of the mechanic, and the cost of any parts that need to be replaced. It is advisable to get a few quotes from different mechanics for comparison.

10. Can OBDII code P1574 GMC cause other problems in my vehicle?

While this code specifically relates to the stop lamp switch circuit, unresolved issues with it can potentially lead to other problems such as issues with the cruise control system, shifting gears, or overall electrical malfunctions in the vehicle.