How JustAnswer Works:

 
 
 
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
 
 
 
Ask Eric Your Own Question
Eric, Automotive Repair Shop Manager
Category: Car
Positive Feedback: 99.2 %
Satisfied Customers: 20561
Experience: Automotive Repair Shop Manager, Technician/JA Mentor
Type Your Car Question Here...
Eric is online now
A new question is answered every 9 seconds

What are P0504 and P0571 error codes on Hyundai 07 Sonata

Customer Question

No Comment Added

Submitted: 4 years ago.
Category: Car
Picture
Expert:  Eric replied 4 years ago.

Hi,

 

DTC P0504 - brake switch a/b correlation

 

Checking output signals from both brake switch. when all of them are On or OFF simultaneously, if abnormal signal is detected for more than 0.5 sec., an error is recognized. And if this condition lasts for certain period. PCM sets P0504. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till cosecutive 2 driving cycle.

DTC Detecting Condition
Item
Detecting Condition
Possible cause
DTC Strategy
? Comparing 2 brake signals during driving
? Poor connection
? Open or Short
? Faulty PCM
Enable Conditions
Case 1
? Engine works
? Vehicle Speed Sensor is abnormal.
Case 2
? Engine works
? Vehicle Speed Sensor is normal and Vehicle Speed is over 20kph during 1sec or more.
Threshold value
? The one brake signal's change duration when another signal has been changed > 0.5 sec
Diagnosis Time
? Continuous
MIL On Condition
? 2 driving cycles

Specification
Item
During taking off the brake
During stepping on the brake
Brake Lamp Switch
0V
Battery voltage
Brake Switch
Battery voltage
0V

 

 

Component Location

 

Terminal and Connector Inspection
1.Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2.Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3.Has a problem been found? YES ? Repair as necessary and go to "Verification of Vehicle Repair" procedure NO ? Go to " Power Circuit Inspection " procedure.
Power Supply Circuit Inspection
1.Check Voltage
(1)IG Key "OFF".
(2)Disconnect the PCM connector.
(3)IG Key "ON" and keep the brake taking off.
(4)Measure the voltage between terminal 21 of PCM connector and chassis ground.
(5)Measure the voltage between terminal 23 of PCM connector and chassis ground .
(6)Keep the brake stepping on.
(7)Measure the voltage between terminal 21 of PCM connector and chassis ground.
(8)Measure the voltage between terminal 23 of PCM connector and chassis ground .
A.Specification :
Item
During taking off the brake
During stepping on the brake
Brake Lamp Switch
0V
Battery voltage
Brake Switch
Battery voltage
0V

(9)Is the measured voltage within specification ? YES ? Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair as necessary and go to "Verification of Vehicle Repair" procedure. NO ? Go to "Check open in harness" as follows.
2.Check open in harness
(1)IG Key "OFF".
(2)Disconnect the brake switch and PCM connector.
(3)Measure the resistance between terminal 21 of PCM harness connector and terminal 3 of Brake switch harness side.
(4)Measure the resistance between terminal 23 of PCM harness connector and terminal 1 of Brake switch harness side. Specification : Approx. below 1?

(5)Is the measured resistance within specification ? YES ? Go to "Check voltagen" procedure. NO ? Repair open in circuit and go to "Verification of Vehicle Repair" procedure.
3.Check voltage
(1)IG Key "OFF".
(2)Disconnect the brake switch connector.
(3)Measure the voltage between brake lamp switch terminal and chassis ground.
(4)Measure the voltage between brake switch terminal and chassis ground.
(5)Key "ON".
(6)Measure the voltage between brake lamp switch terminal and chassis ground.
(7)Measure the voltage between brake switch terminal and chassis ground.
A.Specification :
Item
During taking off the brake
During stepping on the brake
Brake Lamp Switch
0V
Battery voltage
Brake Switch
Battery voltage
0V

(8)Is the measured voltage within specification ? YES ? Substitute with a known - good brake switch and check for proper operation. If the problem is corrected, replace brake switch and go to "Verification of Vehicle Repair" procedure. NO ? Check the fuse between battery and brake switch. ? Repair open or short in power circuit of brake switch and go to "Verification of Vehicle Repair" procedure.

 

 

DTC P0571 - brake switch A circuit

 

Checking input signals from brake lamp switch. under detecting condition, if the operation state of brake lamp switch does not change for more than 3 sec., PCM sets P0571. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till cosecutive 2 driving cycle.

DTC Detecting Condition
Item
Detecting Condition
Possible cause
DTC Strategy
? PCM detects brake lamp input signal when vehicle stops.
? Poor connection
? Open or short to ground in signal circuit
? Faulty PCM
Enable Conditions
? Engine works
? Vehicle speed signal is normal.
? Vehicle speed >20 kph (during 1sec or more)
Threshold value
? Vehicle speed < 3kph
? Vehicle acceleration< -6kph/s
? Brake lamp "OFF" and not changing of brake lamp signal for more 3 sec.
Diagnosis Time
? Continuous (More than 2 seconds failure for every 2 seconds test )
MIL On Condition
? 2 driving cycles

 

Terminal and Connector Inspection
1.Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2.Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3.Has a problem been found? YES ? Repair as necessary and go to "Verification of Vehicle Repair" procedure NO ? Go to " Power Circuit Inspection " procedure.
Power Supply Circuit Inspection
1.Check voltage
(1)IG "OFF".
(2)Disconnect the PCM connector.
(3)IG "ON" and ENG "OFF"
(4)During taking off the brake : Measure the voltage between terminal 23 of PCM harness connector and chassis ground.
(5)During stepping on the brake : Measure the voltage between terminal 23 of PCM harness connector and chassis ground.
A.Specification :
Item
During taking off the brake
During stepping on the brake
Brake Lamp Switch
0V
Battery voltage
Brake Switch
Battery voltage
0V

(6)Is the measured voltage within specification ? YES ? Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair as necessary and go to "Verification of Vehicle Repair" procedure. NO ? Go to "Check open in harness" as follows.
2.Check open in harness
(1)IG "OFF".
(2)Disconnect the brake switch and PCM connector.
(3)Measure the resistance between terminal 23 of PCM harness connector and terminal 1 of Brake switch harness side. Specification : Approx. below 1?

(4)Is the measured resistance within specification ? YES ? o to "Check voltage" as follows. NO ? Repair open in circuit and go to "Verification of Vehicle Repair" procedure.
3.Check voltage
(1)IG "OFF".
(2)Disconnect the brake switch connector.
(3)Measure the voltage between brake lamp switch terminal and chassis ground.
(4)IG "ON" and ENG "OFF"
(5)Measure the voltage between brake lamp switch terminal and chassis ground.
A.Specification :
Item
During taking off the brake
During stepping on the brake
Brake Lamp Switch
0V
Battery voltage
Brake Switch
Battery voltage
0V

(6)Is the measured voltage within specification ? YES ? Substitute with a known - good brake switch and check for proper operation. If the problem is corrected, replace brake switch and go to "Verification of Vehicle Repair" procedure.. NO ? Check the fuse between battery and brake switch. ? Repair open or short in power circuit of brake switch and go to "Verification of Vehicle Repair" procedure.

 

 

The majority of the time it is a faulty brake switch that sets both codes, but I included testing procedures so that you can verify a faulty switch and not a wiring issue

Ask Your Own Car Question
Customer: replied 4 years ago.

Eric , thank you should I just replace the switch and is it just a plug in type

Expert:  Eric replied 4 years ago.

Hi,

 

 

There are 2 locknuts to remove to remove the brake switch, and disconnect the connector. Install new one in reverse. No special programming or anything:

 

graphic

Eric, Automotive Repair Shop Manager
Category: Car
Positive Feedback: 99.2 %
Satisfied Customers: 20561
Experience: Automotive Repair Shop Manager, Technician/JA Mentor
Eric and 20 other Car Specialists are ready to help you
Ask Your Own Question Now
Customer: replied 4 years ago.

Sweet thank you so much Eric, wish I could pay you more , been laid off a month thanks

Picture
Expert:  Eric replied 4 years ago.

Thanks for the bonus and it is more than plenty - I enjoy being able to help people save some money and do it themselves. Have a great week!

Ask Your Own Car Question

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P Elm City, NC
< Last | Next >
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P Elm City, NC
  • used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future. David L. Richmond, TX
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil Marysville, CA
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles Walnut Creek, CA
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!     Sue Charleston, WV
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff. Jim Castleberry, FL
  • The nearest Volvo dealer is 160 miles away. Best $15 bucks I have spent in a long time! Paul M Corpus Christi, TX
 
 
 

Meet The Experts:

 
 
 
  • Chris (aka-Moose)'s Avatar

    Chris (aka-Moose)

    Technician

    Positive Feedback:

    99.6 %

    Satisfied Customers:

    789
    16 years of experience
< Last | Next >
  • http://ww2.justanswer.com/uploads/MU/muddyford/2012-6-13_1204_1.64x64.png Chris (aka-Moose)'s Avatar

    Chris (aka-Moose)

    Technician

    Positive Feedback:

    99.6 %

    Satisfied Customers:

    789
    16 years of experience
  • http://ww2.justanswer.com/uploads/SU/supermechanic/2012-6-7_133644_FOUNDIT.64x64.jpg Super mechanic's Avatar

    Super mechanic

    Auto Mechanic

    Positive Feedback:

    98.5 %

    Satisfied Customers:

    1893
    ASE master, 30+ years. All makes and models. Trouble shooter, shop forman, service manager
  • http://ww2.justanswer.com/uploads/TE/TedG/2012-6-15_14759_avaLarge.64x64.jpg Ted G.'s Avatar

    Ted G.

    ASE Certified Technician

    Positive Feedback:

    100.0 %

    Satisfied Customers:

    1583
    20 years auto repair experience, ASE Master Tech, Mechanical Failure consultant, Expert Witness
  • http://ww2.justanswer.com/uploads/joecamel90/2008-11-13_03615_head_shot.jpg George H's Avatar

    George H

    ASE Certified Technician

    Positive Feedback:

    99.1 %

    Satisfied Customers:

    1295
    ASE Master Tech 15+ yrs, AAS Automotive Technology, Factory trained Asian specialist
  • http://ww2.justanswer.com/uploads/crzydrvr00/2008-12-18_214629_246347.jpg Richard's Avatar

    Richard

    ASE Certified Technician

    Positive Feedback:

    99.0 %

    Satisfied Customers:

    936
    12 years Ford Lincoln/Mercury Jaguar dealership as a technician and shop foreman reparing all makes
  • http://ww2.justanswer.com/uploads/AM/amedee/2012-11-3_181646_profilepic2.64x64.jpg AMEDEE's Avatar

    AMEDEE

    ASE MASTER TECH

    Positive Feedback:

    97.8 %

    Satisfied Customers:

    2359
    ASE MASTER TECH ADVANCED LEVEL SPECIALIST
  • http://ww2.justanswer.com/uploads/BA/baddad1/2012-5-13_185624_DSC00475.64x64.JPG carguy1's Avatar

    carguy1

    Auto Service Technician

    Positive Feedback:

    99.1 %

    Satisfied Customers:

    2642
    25years experience,certified subaru technician,Nissan factory trained