Porsche

Porsche repair questions? Ask a mechanic for answers ASAP

Ask an Expert,
Get an Answer ASAP!

2004 Carrera 4s. When driving with headlights off, all is…

Customer Question
2004 Carrera 4s. When...
2004 Carrera 4s. When driving with headlights off, all is well. As soon as I turn on the headlights, both the ABS PSM warning lights go on.
Submitted: 2 years ago.Category: Porsche
Show More
Show Less
Ask Your Own Porsche Question
Answered in 8 minutes by:
2/20/2016
Porsche Mechanic: rpmdiag, Tech and Instructor replied 2 years ago
rpmdiag
rpmdiag, Tech and Instructor
Category: Porsche
Satisfied Customers: 8,867
Experience: Since 1975
Verified

Hi, I’m Ron and I can help you.
I have been in this business since 1975 and also teach automotive repair. I am confident we can resolve your problem together. Please understand that I don't know your skill level. I can't see, smell, hear, or touch the vehicle either, so it may take a few replies to get to satisfactory results. Please be patient!
I also try to give all of the information you may need, expecting a “positive rating” in return. I will also continue assisting you after you have rated me, if necessary. If there is any reason I cannot get a positive rating, please let me know why “in advance”, so I can go another direction for you. I am sorry you’re having this problem; I’ll help you through it.

This is module related and is most likely caused on the BUS line. You need to attach a scan tool to not only read codes, BUT also read data from node to node with bi-directional tests.

Thanks, Ron

Ask Your Own Porsche Question
Customer reply replied 2 years ago
I am aware of the fact that I can take the C4s in for diagnostic. All it takes is a couple big, I just thought that someone with your experience could listen to the symptom and come up with something to try before needing an appointment with my local Porsche shop. The fact that the warning lights only go on when the headlights are activated indicates that the problem is not related to the ABS and/or the PSM. I just drove the car 1200 miles with the lights off without throwing a code.
Porsche Mechanic: rpmdiag, Tech and Instructor replied 2 years ago

My database is down right now so I am letting Frank take over.

Thanks,

Ron

Ask Your Own Porsche Question
Porsche Mechanic: Pete, Technician replied 2 years ago
Pete
Pete, Technician
Category: Porsche
Satisfied Customers: 32,574
Experience: 17 years automotive training and experience.
Verified

Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay.

This definitely sounds like a low voltage issue here causing this.When the head lights are on this draws a large amount of power from the battery and if there is any issues with a weak alternator or battery or a fault with the battery cables themselves being corroded or loose this causes this here.I would start off with having the cables checked to see if any are loose or corroded at all.If a fault is found it will need repaired.If these are checked and found to be o.k. I would have the alternator and battery tested to see if either are at fault needing replaced.A local parts store will usually test both of these at no charge to you.If these are all found to be o.k. let me know.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.

Thanks Pete

Ask Your Own Porsche Question
Porsche Mechanic: porscheguru, Porsche technician replied 2 years ago
porscheguru
porscheguru, Porsche technician
Category: Porsche
Satisfied Customers: 396
Experience: Exclusive Porsche only technician for over 28 years
Verified

Hi, I am going to be helping you with this and please reply when you are at the car. Since these cars are getting older, we are starting to see some issues with the wiring harnesses. I can have you take a quick look at something to see if that is the reason you are having this problem. It is Sunday, and I have some errands to run but I will have my phone and I will be alerted when you return to this chat. Disregard the "I'm ready to be rated" because it is selected but I can not deselect it.

Ask Your Own Porsche Question
Porsche Mechanic: Clifton B., Auto Service Technician replied 2 years ago
Clifton B.
Clifton B., Auto Service Technician
Category: Porsche
Satisfied Customers: 4,792
Experience: Master Auto Tech
Verified

hi do you have any water are moisture in any of the tail or head lights >>?

Ask Your Own Porsche Question
Customer reply replied 2 years ago
I hear you.This problem arose during the wet season. I drive my 4s cab as fast as I can within the limits of inertia and road conditions. I hit the rev limiter in 5th gear often. When lights pop up it is a concern. This car is a ski machine not a garage queen. Checked the headlights, they have moisture. I will take them apart as soon as I have free time. I don't f**k with cars when we have pow days. I change oil at 3000 miles and pay attention to indicators.
Porsche Mechanic: Clifton B., Auto Service Technician replied 2 years ago

ok please rate the service before you go and let me know after you clean and seal the light if you still have the problem .

Ask Your Own Porsche Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a porsche mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Clifton B. Your Own Question
Clifton B.
Clifton B.
Clifton B., Auto Service Technician
Category: Porsche
Satisfied Customers: 4,792
4,792 Satisfied Customers
Experience: Master Auto Tech

Clifton B. is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

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 PElm 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.

PhilMarysville, 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.

CharlesWalnut 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!

SueCharleston, 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.

JimCastleberry, FL

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

< Previous | Next >

Meet the Experts:

Sebastian Vizcarra

Sebastian Vizcarra

Porsche Meister Tech

350 satisfied customers

Porsche Factory Certified Master Technician

Matt

Matt

Engineer - BEng Hons

552 satisfied customers

Mechanical Engineer with 20 years experience in the auto industry, 8 yrs in formula 1 engine testing

PorscheDoc

PorscheDoc

Independent Porsche shop owner

355 satisfied customers

20 years of experience working with Porsche. Independent European shop owner and technician.

Stephen D

Stephen D

Technician

67 satisfied customers

5+ years managing an auto repair shop. Developed a wealth of Porsche knowledge over many model years.

Mike S.

Mike S.

ASE Certified Technician

59 satisfied customers

Porsche mechanic.

Mike Kelly

Mike Kelly

Porsche Mechanic

51 satisfied customers

17 years experience as an auto mechanic, foreign and domestic. 5 years running my own repair business.

Don - Mo Lurch

Don - Mo Lurch

Mechanic

32 satisfied customers

Line Mechanic, Mobile Electronics, Aftermarket Equipment

< Previous | Next >

Related Porsche Questions
2003 Porsche Carrera: trunk latch..engine compartment..works fine
I have a 2003 Porsche Carrera 4S The trunk latch will not release. I have tried the battery emergency overide at the fuse box but it does not work. I think the electric release switch is no longer abl… read more
Sebastian Vizcarra
Sebastian Vizcarra
Porsche Meister Tech
Vocational, Technical or Trade Scho
350 satisfied customers
Porsche Expert, I'm considering the car below and am
Hi Porsche Expert, I'm considering the car below and am wondering about potential IMS bearing problem or any other major problem (rear man seal?) I should look at before buying? Thanks John2004 Porsch… read more
eauto
eauto
self employed
High School or GED
74 satisfied customers
I have a maintenance question for Porche aficionados. I have
Hi, I have a maintenance question for Porche aficionados. I have 50-60K to spend on a new car and know I want another Porsche 911. Do I want to buy a older air cooled Porsche 911 (if I can find one in… read more
Matt
Matt
Engineer - BEng Hons
Bachelor's Degree
552 satisfied customers
I am considering buying a 2004 Porsche 911 Carrera 4S AWD
I am considering buying a 2004 Porsche 911 Carrera 4S AWD Convertible for 30K+taxes and registration. It has 71K miles on it. It had the IMS bearings fixed and one clutch replacement at 30K miles. The… read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
Super fast drain on a brand new fully charged battery.....
super fast drain on a brand new fully charged battery..... 03 996 cabriolet porsche … read more
Mike S.
Mike S.
ASE Certified Technician
Vocational, Technical or Trade Scho
59 satisfied customers
I just have a Piwis II Version 17.5, 997 targa 4 S year
hello JA: Hi. How can we help? Customer: I just have a Piwis II Version 17.5 JA: What is the model of your '17 Porsche? Customer: 997 targa 4 S year 2007 JA: Are you fixing your Targa yourself? What h… read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
I have a 2003 carrera 4s ,and every 800to1000 miles it uses
i have a 2003 carrera 4s ,and every 800to1000 miles it uses about 1 quart of 15/50 mobil oil. what could be the problem it has 98000 miles on it.… read more
Gary
Gary
Senior Technician
Vocational, Technical or Trade School
92 satisfied customers
I had my car serviced last week. Clean bill of health. Only
I had my car serviced last week. Clean bill of health. Only 20,000 miles, despite it being a 2006 911 Carrera 4s. I left my car with the garage attendant. It was I left my car with the garage attendan… read more
Kevin
Kevin
workshop foreman /master tech/mot tester
1 satisfied customers
Porsche 911 Carrera 4S: my name is ***** ***** montreal,hope
hi my name is ***** ***** montreal,hope i can fix this problem without going to the dealer.. i have a 997 4s- 06 , the cel light when on and the engine start to hesitate and loose power , feels like w… read more
porscheguru
porscheguru
Porsche technician
396 satisfied customers
I have 2007 porsche carrera 4s the pasm failure comes on the
I have 2007 porsche carrera 4s the pasm failure comes on the screen on and off what does it mean … read more
porscheguru
porscheguru
Porsche technician
396 satisfied customers
Porsche 911 Carrera 4S - Cab: 2004 c4s cab - top operates properly
2004 c4s cab - top operates properly open and close. But when closed the dash light remains on. Preventing rear windows to operate. If I keep my hand on the "Close Top" switch the latch opens and clos… read more
Pete
Pete
Technician
32,574 satisfied customers
Porsche Carrerra 4S: I have a 2013 Carrera 4S; when I back
I have a 2013 Carrera 4S; when I back out or turn in sharply or take sharp turns, it feels very funky, like it is a four-wheel drive jeep still in 4-wheel drive. What is up with this… read more
Matt
Matt
Engineer - BEng Hons
Bachelor's Degree
552 satisfied customers
Porsche 911 Carrera 4S: 2009 911 c4s. have had long problem
2009 911 c4s. have had long problem with starting. sometimes when you turn the key nothing happens. sometimes, you have to turn the key several times before it starts and then when it starts, it dies … read more
Matt
Matt
Engineer - BEng Hons
Bachelor's Degree
552 satisfied customers
Porsche 911 Carrera 4S: why am i getting water on the back
why am i getting water on the back passenger seat pan and floor in my 06 porsche carrera 4s convertible?… read more
porscheguru
porscheguru
Porsche technician
396 satisfied customers
Porsche 911 Carrera 4S: I put a new battery in my 2006 C4S
I put a new battery in my 2006 C4S yesterday, and today it failed an emission inspection because of no codes. What is the drive cycle for this car?… read more
porscheguru
porscheguru
Porsche technician
396 satisfied customers
Porsche 911 Carrera 4S: I just bought a 2004 carrera 4 s,,and
I just bought a 2004 carrera 4 s,,and thé speed control is not working, I want to Know where to begin Thank you Gylis… read more
Mark B
Mark B
Vocational, Technical or Trade Scho
90 satisfied customers
Porsche 911 Carrera 4S Where is the battery location on a
Where is the battery location on a Porsche 2006 Carrera. Also , I see that poeple are asking about opening the engine campartment and hood after the battery dies, how do we do that?… read more
Sebastian Vizcarra
Sebastian Vizcarra
Porsche Meister Tech
Vocational, Technical or Trade Scho
350 satisfied customers
Porsche Carrera: Cabriolet..only 5,000 miles on it..warranty..put back
I am about to purchase my dream Porsche - a 2006 Yellow Porsche Carrera 4S Cabriolet with only 25,000 kms. My concern is that when the original owner purchased it from Florida with only 5,000 miles on… read more
Sebastian Vizcarra
Sebastian Vizcarra
Porsche Meister Tech
Vocational, Technical or Trade Scho
350 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x