Cadillac

Cadillac Repair Questions? Ask a Mechanic for Answers ASAP

Ask an Expert,
Get an Answer ASAP!

Cadillac
This answer was rated:

I've got a '03 cadillac dts 4.6L northstar in here and i

Hey man, I've got a...
Hey man, I've got a '03 cadillac dts 4.6L northstar in here and i have a fuel level sensor code. Voltage too high. i know via wiring diagram that the purple wire is the signal wire from the sending unit to the pcm. However, i have 5 volts on said signal wire. i went straight to the pcm and cut the signal wire just before the pcm C2 connector and i still have 5 volts {reference voltage} coming out of the pcm. with the exception of the pcm being internally shorted im out of ideas.
Show More
Show Less
Ask Your Own Cadillac Question
Answered in 1 minute by:
10/18/2017
Amedee
Amedee, Cadillac Technician
Category: Cadillac
Satisfied Customers: 26,898
Experience: ASE certified Technician advanced level specialist. Wisconsin certified emissions state inspector
Verified

Hello and welcome!

My name is ***** ***** I can assist you with your question.

Ask Your Own Cadillac Question

Are you saying you have 5 volts on this purple wire leaving the PCM after you cut this wire?

May I get the code you have stored in the computer?

Thank you

Ask Your Own Cadillac Question
Customer reply replied 1 month ago
5 volts after out of the pcm after cutting the wire.
Customer reply replied 1 month ago
p0463

Thank you.

One minute please

Ask Your Own Cadillac Question

Thank you for your patients.

The 5 volts coming out of the PCM is normal. This is OK. This is how the system works.

However, the sending unit should pull this voltage down depending on the fuel level in the tank.

Ask Your Own Cadillac Question
Customer reply replied 1 month ago
the variable resistor in the tank should pull down voltage to an acceptable value?
Customer reply replied 1 month ago
of course corresponding to the fuel level. more fuel is higher voltage?

YES sir thats correct.

I would plug everything back in, hook everything back up and recheck the voltage on this purple wire. It should move or change as the float level is changed.

The manufacturer only provides the resistance specs. If you want to ohm out the sending unit, the specification is 250 ohms when full and 40 ohms when the tank is empty.

Of course, be sure the black wire has a good ground.

Ask Your Own Cadillac Question
Customer reply replied 1 month ago
but i thought the voltage should cap out at 3.5 volts i dont understand what i should see on the signal wire then.

Just be sure it varies when the float goes up and down.

With the connector plugged into the sender, be sure the voltage on the purple wire is NOT 5 volts. If so, there is a problem. When the resistance goes up (when the tank is full) the voltage will be low.. because of more resistance.

When the resistance is low, the voltage will be higher.

Does that make sense?

Ask Your Own Cadillac Question
Customer reply replied 1 month ago
i get it that the resistance should change but i'm failing to convert that to voltage change. and it is 5 volts with everything connected
Customer reply replied 1 month ago
that's what started me on the path to the pcm.
Customer reply replied 1 month ago
how do i stop this site from sending me text messages every time you reply?

Got it!

I would check the resistance specs of the sending unit next.

Also, check the ground on the black wire. It could be a faulty ground preventing the voltage from being pulled down with everything connected. That would explain the 5 volts on the purple wire.

I am sorry, I don't know anything about text messages sent from the site.

Ask Your Own Cadillac Question

I am glad I can help!

Please don't forget to honor your good faith deposit by rating my answer as "5 STARS or SMILEY FACES" for assisting you today.

Keep in mind, we can still continue this conversation at no further cost to you even after you rate my answer. Just reply back to me using this page and I will get it and get back to you ASAP!

I just ask that you allow time in between replies as I may be helping other customers or offline spending time with the family.

Also, if you are a member or if you have a subscription to the site, you still need to rate my answer in order for me to get credit for assisting you with your question.

You should see the rating system towards the top of the page.

Please let me know if you have any further questions.

Thanks and have a great day!!

Amedee
Amedee, Cadillac Technician
Category: Cadillac
Satisfied Customers: 26,898
Experience: ASE certified Technician advanced level specialist. Wisconsin certified emissions state inspector
Verified
Amedee and 87 other Cadillac Specialists are ready to help you
Ask your own question now
Ask Amedee Your Own Question
Amedee
Amedee
Amedee, Cadillac Technician
Category: Cadillac
Satisfied Customers: 26,898
26,898 Satisfied Customers
Experience: ASE certified Technician advanced level specialist. Wisconsin certified emissions state inspector

Amedee 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:

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

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.

DianeDallas, TX

< Previous | Next >

Meet the Experts:

Jerry Newton

Jerry Newton

Cadillac Technician

1,569 satisfied customers

ASE Master Technician, L1, Master GM Technician. Over 20 years of bumper to bumper GM experience.

Dave Nova

Dave Nova

Cadillac Technician

1,522 satisfied customers

ASE Master Certification. GM World Class Certification

Gm Tech (Cam)

Gm Tech (Cam)

Cadillac Mechanic

1,001 satisfied customers

GM Grand Master Technician 2007. 14 years experience.

John

John

ASE Certified Technician

941 satisfied customers

ASE CERTIFICATIONS A1-A8 & L1 / 40 YEARS AUTOMOTIVE EXPERIENCE

George H.

George H.

ASE Certified Technician

775 satisfied customers

ASE Master Tech 15+ Years

Chris (aka- Moose)

Chris (aka- Moose)

Cadillac Technician

741 satisfied customers

16 years of experience

Don - Mo Lurch

Don - Mo Lurch

Cadillac Technician

690 satisfied customers

GM, Cadillac Cert., Heavy Line Mech, Race Shop Owner, Mobile Electronics.

< Previous | Next >

Related Cadillac Questions
Power steering fluid leaked on to the driver side floor in
Power steering fluid leaked on to the driver side floor in vehicle … read more
eauto
eauto
self employed
High School or GED
74 satisfied customers
2005 sts v8 4.6 109k, transmission was not shifting good,
2005 sts v8 4.6 109k, transmission was not shifting good , would drop into neutral out of the blue.. I had transflush and filter changed the fluid was black, the trans place told me to get rid of car,… read more
kalamykid
kalamykid
Pactor automotive
Vocational, Technical or Trade Scho
97 satisfied customers
My rear window on cadillac escalade 2007 does not open
My rear window on cadillac escalade 2007 does not open anymore after pressing the button on the remote. I often don;t have to open the whole trunk so I open the window only. … read more
Gm Tech (Cam)
Gm Tech (Cam)
Cadillac Mechanic
Vocational, Technical or Trade Scho
1,001 satisfied customers
Ecm I'm looking for looking location to replace it
Ecm I'm looking for looking location to replace it … read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
I have an 1986 cadillac deville. The driver's information
I have an 1986 cadillac deville. The driver's information center does not display. I can push a button to make the km show in miles/gallons to liters. But the screen in front of the shifter does not r… read more
roy
roy
Associate Degree
3 satisfied customers
I have a 2006 cts switched the motor battery was out of the
i have a 2006 cts switched the motor battery was out of the car for 2 weeks i am now locked out. tried a 10 min relearn when you go from crank to on the security light goes out and comes back on after… read more
kalamykid
kalamykid
Pactor automotive
Vocational, Technical or Trade Scho
97 satisfied customers
How to reset theft system on my cadiiiac, 1990 eldor. I
how to reset theft system on my cadiiiac , 1990 eldor. … read more
Frankie Pintado
Frankie Pintado
Lead Technician
Vocational, Technical or Trade School
0 satisfied customers
Changed waterpump and changed thermasate water not flowing
changed waterpump and changed thermasate water not flowing radiator good … read more
David Craig
David Craig
OWNER/MECHANIC
Associates
4,072 satisfied customers
Looking for an experienced technician on Cadillacs. 2006
looking for an experienced technician on Cadillacs … read more
kalamykid
kalamykid
Pactor automotive
Vocational, Technical or Trade Scho
97 satisfied customers
Trunk latch works if up but not when closed. It is not a
It is not a lubrication problem but it is electrical … read more
Frankie Pintado
Frankie Pintado
Lead Technician
Vocational, Technical or Trade School
0 satisfied customers
Are there any ballast off brands that will work on dts 2006
are there any ballast off brands that will work on dts 2006 cadillac … read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
Remote keys got washed and now alarm is going off every 10
Remote keys got washed and now alarm is going off every 10 min … read more
Frankie Pintado
Frankie Pintado
Lead Technician
Vocational, Technical or Trade School
0 satisfied customers
07 escalade esv fuel pressure is within specs. koeo but
07 escalade esv fuel pressure is within specs. koeo but reads over 120 psi with engine running. Getting codes P0172 & P0175 both banks running rich.injector pulse time is 2.3 ms. at idle engine at ope… read more
rpmdiag
rpmdiag
High school
7,169 satisfied customers
1996eldorado water leak in head. 1996 eldorado. Do they make
1996eldorado water leak in head JA: What part of the car is the leak coming from? And are you sure it's water? Customer: yes JA: What is the model/year of your Cadillac? Customer: 1996 eldorado JA: Ar… read more
ggrote1
ggrote1
Vocational, Technical or Trade Scho
13 satisfied customers
I have a 2011 sts caddy it was stolen last night can it be
I have a 2011 sts caddy it was stolen last night can it be tracked my last 8 dig of my vin is BO147902 … read more
heavy_chevy_396
heavy_chevy_396
Vocational, Technical or Trade Scho
2,518 satisfied customers
My car is overheathing change radiator but has no
my car is overheathing change radiator but has no thermostat … read more
fordguy4u
fordguy4u
Automotive Tech
Vocational, Technical or Trade Scho
70 satisfied customers
Gas is getting to fuel filter, ive replaced the fuel relay
gas is getting to fuel filter, ive replaced the fuel relay fuse and filter. the truck will start with ethenol, or starting fluid. but will not start with just gas … read more
roy
roy
Associate Degree
3 satisfied customers
2008 Cadillac Escalade AWD 6.2 Vortec Started getting a
2008 Cadillac Escalade AWD 6.2 Vortec Started getting a P1175 Fuel Trim Balance Bank 2 at 55k miles last year. Took to dealer, 1st time they found nothing, they ran a fuel injection clean and said the… read more
Gm Tech (Cam)
Gm Tech (Cam)
Cadillac Mechanic
Vocational, Technical or Trade Scho
1,001 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