Dodge

Dodge Repair Questions? Ask a Mechanic for Answers ASAP

Ask an Expert,
Get an Answer ASAP!

Dodge

I have a 2001 Dodge Ram 2500 4x4 diesel and the speedometer

Customer Question
goes on and off at...
I have a 2001 Dodge Ram 2500 4x4 diesel and the speedometer goes on and off at randum. It works great for a while and then suddenly goes to zero. It will stay on zero for a while and then suddenly starts working and continues this cycle at random. All the other gages and tach work properly. No lights ever appear. This has been going on for nearly a year now and no one seems to know what the problem is. I think it may be a loss of the input signal since the cruise control disengages when the speedometer goes to zero. I have replaced the ABS sensor in the rear axle. That did not help. Is there another sensor somewhere else?
Submitted: 2 years ago.Category: Dodge
Show More
Show Less
Ask Your Own Dodge Question
Answered in 39 minutes by:
10/6/2015
Dodge Mechanic: bill, dodge master tech replied 2 years ago
bill
bill, dodge master tech
Category: Dodge
Satisfied Customers: 1,634
Experience: 25 years with dodge drivability and electrical expert
Verified

the speedometer signal originates at the rear speed sensor on the rear axle, it then goes to the abs controller and engine computer (PCM NOT The diesel ECM) where it then travels to the speedometer, since you already replaced the speed sensor and there are no lights coming on we can ASSUME (remember I am basing this on information you supplied and any info you supply in the future) the wiring is ok to the abs controller ( it would set a fault and turn on the abs light IF the sensor was dropping out) the abs controller then communicates the signal via a digital square wave to the PCM which then hardwires the signal to the cluster, no based on what info you provided about the cruise control dropping out when the speedo drops out we can ASSUME the wire from the PCM to the cluster is ok that leaves the PCM either not receiving the signal from the abs controller or an internal failure in the PCM itself, to get a BEST GUESS you will need to scan the PCM and see if it logged any faults for a loss of sped signal if it DID NOT then a good ASSUMPTION would be a failure in the pcm itself, this is assuming the connections have no corrosion and are tight

Ask Your Own Dodge Question
Customer reply replied 2 years ago
Thank you. I pretty well knew everything you told me except I thought there may be another sensor somewhere. My next question is: can you scan the PCM for error codes even if the speedo is working? I have been to a Dodge dealer twice and they seemed to think that they could not come up with an error code when the speedo is working. I live in the middle of nowhere, the nearest dealer is 250 miles away and I never know when the speedo will be working or not.
Customer reply replied 2 years ago
I don't want to make a 500 mile round trip for nothing. Need advice about what to do.
Dodge Mechanic: bill, dodge master tech replied 2 years ago

if there is a fault the PCM will store a code any dealer should know this the ONLY time a code is erased is if you erase it with a battery disconnect OR with a scan tool, it MAY self erase AFTER 255 starts with NO repeat of the fault.

you can always purchase a decent scan tool (code readers are very spotty on the OLDER diesels) for a few hundred bucks or less amazon has quite a few BUT I would contact the manufacturer and verify it will work on your truck, 01 is a changeover year and can have several versions of the cummins from 12 valve to 24 valve with the 24valve having a dedicated ECM for the engine.

we have not used dedicated speed sensors for some time and on the trucks with rear abs or 4 wheel abs the signal is from the rear sensor no others are needed or used.

if you have a scan tool that reads data you can see if the PCM is losing the signal BUT without a way to see if the digital square wave is actually being sent to the PCM you will need to rely on scan data and any faults in the PCM

remember talking to a service writer is NOT the same as talking to a tech on the phone many writers have little actual experience working on vehicles so their info can be spotty

Ask Your Own Dodge Question
Ask bill Your Own Question
bill
bill
bill, dodge master tech
Category: Dodge
Satisfied Customers: 1,634
1,634 Satisfied Customers
Experience: 25 years with dodge drivability and electrical expert

bill 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 AM VERY GLAD THAT I TOOK A CHANCE ON YOUR PROBLEM SOLVING SKILLS. I WAS SUCCESSFUL IN REPLACING THE FUEL PUMP. MY TRUCK RUNS LIKE A CLOCK. IT RUNS LIKE THE DAY I BOUGHT IT. NO LUNGING FORWARD, THE TURBO REACTS THE SECOND I STOMP ON THE GAS, AND IT HAS A LOT MORE POWER AND EVEN SOUNDS BETTER TO ME. IT SAVED ABOUT $500.00 BY DOING THE WORK MYSELF. I GIVE YOU ALL THE CREDIT FOR YOUR DIAGNOSING THE PROBLEM, JUST FROM THE SYMPTONS I GAVE YOU OVER THE e MAIL. I WILL USE YOUR WEB SITE AGAIN AND REFER MY FRIENDS. THANKS SO MUCH FOR THE HELP.

TOM WHITTAKERUSA

Just a quick line to tell you how pleased I am to have my brakes working properly after all this time. Your answer was what I needed. I would certainly recommend you highly. God bless!

Rev. Jerry BaysingerHolts Summit, Mo

I recently asked a question about my 2005 dodge ram, and I just wanted to let my Expert know that he hit the nail squarely on the head with his answer. I wanted to thank him again.

GregPittsburgh, PA

Just a quick line to tell you how pleased I am to have my brakes working properly after all this time. Your answer was what I needed. I would certainly recommend you highly. God bless!

JerryHolts Summit, MO

I was skeptical at first but thought I'd give it a try. I was pleasantly surprised. Your site actually is a quality service that I would recommend to others in a heartbeat.

StanSayre, PA

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

< Previous | Next >

Meet the Experts:

Jerry

Jerry

Master Mechanic

1,754 satisfied customers

ASE Master tech, 30 years exp. troubleshooter, driveability tech

Chris

Chris

Shop Foreman

6,613 satisfied customers

Dodge/Cummins and Chrysler Certified Master Tech

Mopar Certified

Mopar Certified

Dodge Technician

5,931 satisfied customers

24 Year Chrysler/Dodge Certified Specialist

moparfl

moparfl

ASE Certified Technician

3,292 satisfied customers

ASE Master Tech Gold level Chrysler Status 30 years dealership exp

Dodgerench

Dodgerench

ASE Certified Technician

2,809 satisfied customers

30+ years Dodge/Chrysler exp., ASE Master with L1 certification. Driveability/ combustion specialist

Tim Mohr

Tim Mohr

ASE MASTER TECH

2,298 satisfied customers

30 YRS EXPERIENCE, FOREIGN AND DOMESTIC, GAS AND DEISEL

Don - Mo Lurch

Don - Mo Lurch

Aftermarket & Factory Electronics

1,562 satisfied customers

Cert. Dodge & Chrysler Warnty, Heavy Line Mech, Mobile Electronics. Sales, Installation & Repair for 30 years

< Previous | Next >

Related Dodge Questions
Traction control and cruise control. 6.7 l. Ram 3500. 2014.
I had it into the dealer to fix some recalls. get it back and this is now an issue … read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
My 2010 ram 2500 Will not start... no lights, radio or
My 2010 ram 2500 Will not start... no lights, radio or anything. When connected to the charger, it only gives me a light what the mileage normally shows, reading no fuse.… read more
Chris (aka - Moose)
Chris (aka - Moose)
Vocational, Technical or Trade Scho
108 satisfied customers
1999 ram 2500 5.9 ltr turns over OK but misfires and will
1999 ram 2500 5.9 ltr turns over OK but misfires and will not start. Has 40psi fuel pressure. No water in gas. Replaced battery, plugs, plug cables, distributor cap, rotor, and plate, and substituted … read more
Dodgerench
Dodgerench
ASE Certified Technician
Vocational, Technical or Trade Scho
2,809 satisfied customers
Thought it was a starter issue. '97 ram 2500 12 valve
thought it was a starter issue JA: When you turn the key, do you get a single loud click, or a series of rapid ones? Customer: yes JA: What is the model/year of your Dodge? Customer: '97 ram 2500 12 v… read more
AMEDEE
AMEDEE
AUTOMOTIVE TECHNICIAN
Vocational, Technical or Trade Scho
9,105 satisfied customers
2016 Dodge Ram 2500 6.4 hemi. Vin#3c6ur5cj8gg324805. Where
2016 Dodge Ram 2500 6.4 hemi. Vin#3c6ur5cj8gg324805. Where is the ambient temp sensor located. I️be like around the mirror housing and don't see it.… read more
fordguy4u
fordguy4u
Automotive Tech
Vocational, Technical or Trade Scho
70 satisfied customers
2007 Dodge Ram 2500 5.7L engine When the vehicle is warmed
2007 Dodge Ram 2500 5.7L engineWhen the vehicle is warmed up and running for a while, just sitting at an idol the vehicle stumbles in stalls. The fuel pressure is good when this happens and there are … read more
eauto
eauto
self employed
High School or GED
74 satisfied customers
Cruise control not working and can't turn off traction
cruise control not working and can't turn off traction control. My vehicle is 2006 Magnum SE*****w/2.7liter 6cyl. 111.300 miles. no check lights cruise in operable as is esp. switch and it sounds like… read more
Chris
Chris
Shop Foreman
6,613 satisfied customers
2016 ram 2500 diesel fan clutch won't disengage. Fan is
2016 ram 2500 diesel fan clutch won't disengage. Fan is always engaged. … read more
Chris
Chris
Shop Foreman
6,613 satisfied customers
2001 dodge ram 2500 diesel, fuel sending unit is not
2001 dodge ram 2500 diesel, fuel sending unit is not working. Things I tried. pulled fuel tank and pulled sending unit out and checked voltage, (less than a volt), checked blue and whit wire at C3 at … read more
AMEDEE
AMEDEE
AUTOMOTIVE TECHNICIAN
Vocational, Technical or Trade Scho
9,105 satisfied customers
2006 ram cruise control light comes on when on switch is
2006 ram cruise control light comes on when on switch is pressed but immediately goes out when set is pressed. Will not come back on till the truck is shut back off.… read more
Chris
Chris
Shop Foreman
6,613 satisfied customers
How do you adjust the power driver seat in a 2003 ram 2500.
how do you adjust the power driver seat in a 2003 ram 2500 … read more
Chris
Chris
Shop Foreman
6,613 satisfied customers
I have a 2007 dodge ram 2500 diesel truck with 2 batteris
i have a 2007 dodge ram 2500 diesel truck with 2 batteris and today the battery on the passenger side got very hot and blew tha cap off so is the altenator bad ? i would think the voltage regulator is… read more
BOBBYSS
BOBBYSS
TECHNICIAN/ADVISOR
Associate Degree
8,343 satisfied customers
2003 Dodge Ram 2500 cummins..lampout light and chime comes
2003 Dodge Ram 2500 cummins..lampout light and chime comes on when I use my turn signals...This happens only with the lights turned on at night. … read more
Chris
Chris
Shop Foreman
6,613 satisfied customers
Cruise control will not reset after tapping the break. have
cruise control will not reset after tapping the break. have to pull over, shut down and restart to reactivate cruise control … read more
Brad
Brad
Technician at Dodge Dealership
Vocational, Technical or Trade Scho
12 satisfied customers
Cruise control turns on but will not set I'm reading your
Cruise control turns on but will not set I'm reading your response to same question … read more
Chris
Chris
Shop Foreman
6,613 satisfied customers
Cruise control turns on but won't set. 4.7 v8 haven't
yes if able. Just got the truck a week ago Saturday. Read on blog could be bad vacuum hose. Looking for a diagram for the vacuum hose if fuse isn't bad … read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
Intermittent cruise control malfunctions, 5.9 24v cummins.
It acts like it doesn't maintain the control and doesn't hold on hills as it did for years. It just acts like the cc is not holding where it has been set.… read more
Robert R
Robert R
Auto Technician
Vocational, Technical or Trade Scho
879 satisfied customers
🙂, It's my cruise control, Oops 🙂 it's a 2011 Dodge
Oops 🙂 it's a 2011 Dodge Journey. The engine is the 6 cylinder sorry I don't recall the actual size. … read more
Robert R
Robert R
Auto Technician
Vocational, Technical or Trade Scho
879 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