Sudden Death Mystery

[rr2241tx]

My 2004 2500HD has been rock solid since new…until it died last month. 6.0L, automatic, 4X4, 160K. Idling in line at Walgreens and it flashed a bunch of idiot lights and the AC and radio quit. A few minutes later it started and ran fine to go home but would not crank once home. Serpentine belt is good. No alternator light but battery suggested I drove home without an alternator. Replaced the battery and it made no difference. Towed to shop. Shop billed a months’ retirement and said they replaced the PCB, whatever that is. Made one trip to town and it died three times in traffic in under 10 miles. Towed again! Mechanic has had it two weeks and cannot diagnose the cause. I’m going to have to have it towed somewhere else now.

Any of you ever seen this? I could sure use some guidance.

 

[Sam Colt]

Do you park outside? I’d suspect small mammals.

 

[FireInTheWire]

Mice maybe?

My F150 did the same thing out of the blue. Shop had it for a bit. They ended up reflashing the CPU. They said it lost its mind for some reason. They also said they have never seen that before in a f150

 

[Otto_Mation]

I would check the ground straps to see if they have corroded to the point of falling apart. Below is a link to the electrical diagram for your truck. Also a picture of what the ground straps look like. Based on the symptoms that you described I would start at G104, G106 and G107 on the diagram.

https://portal-diagnostov.com/en/20...ilverado-2500-hd-2004-system-wiring-diagrams/

They might look like a battery cable like this but connected to the frame.

 

[Otto_Mation]

Here is a video of the problem being diagnosed after a dealer could not fix the truck after the owner paid them $3900 in unnecessary repairs.

 

[BeatTheTunaUp]

Check the crank pos sensor. It'll cause hard start and dieing issues. Was the tach erratic?

 

[Slimshaddy]

My best advice to you or anyone who does not have a top notch tech for repairs is to
go the the "IATN" web page and do a search in your area for IATN members near you.
These guys have access to tens of thousands of fixes for impossible to repair problems, all makes, all models.
Techs from all brands of new car dealerships plus tens of thousands of the best Techs in America are members and all contribute to the knowledge base that's available to all members.
I was a member back in the day and their resources saved my ass on more than one occasion when a problem child showed up in my bays.
All recalls start at the dealership service area and when enough of the same problem pops up, it gets referred up too corporate and then it gets or does not get upgraded to a campaign or even recall status.
Point is, that the dealership Techs see the problems first and with help from the factory come up with a fix.
These same techs report to IATN right away so it saves months and months of normal Techs scratching head and wondering what's up while the IATN members get the info right away.

 

[leVieux]

<>

What I’m repeatedly hearing from the “factory-trained” dealer “technicians” lately is that, if the computer can’t diagnose the problem; there IS NO problem, no matter the failures to perform.

Mt brand-new JEEP stopped dead at 300 miles.

Report was “We can’t find anything wrong.”

“OK, start it up and let’s take a ride.”

“Well, it won’t start.”

”How in the Hell can you say there there is nothing wrong when the Dealer’s Shop can’t even start it?”

How confidence-inspiring !

leVieux

<>

 

[Slimshaddy]

The situation at the dealership/s is this..while there MAY be a tech there with the training to do advanced performance and computer diagnostics, the fact is that he is making more than 100K a year and never ventures near the warranty repairs area so unless you are a paying customer your car won't see the brain surgeon, just the entry level tech.
The people who interface with the public know less than nothing about engines, fuel systems, or diagnostics.
They couldn't change the spark plug in a lawn mower, if they even knew what a spark plug was.
Dealership warranty techs rely on what's called "pattern failures" which means when enough of your type of vehicle fails in the exact same way as all the others, somebody at the corporate level will dispatch a tech with L1 certification and the problems will get a solution, after which the data is transmitted to all dealerships and your mystery problem becomes campaign #1569 and has a booklet or web page to instruct the parts changers on which parts to swap out.
I know, I have L1 certification and through my contacts at IATN and my own warranty nightmares at a Honda dealership, found out how it works or rather how it fails to function.

What is ASE L1 certification?

The Automobile -‐ Advanced Engine Performance Specialist (L1) is an advanced level certification from ASE. It is geared toward technicians who perform diagnosis and repairs on the emission control and computer systems of modern automobiles and light trucks.

 

[G O B]

Check the connections on the fuse block. The feed comes in to a stud, and the nut backs off, causing mayhem. I once bought a k2500 Sub for 2 grand because of this problem. Dealers mech could not find, took about 20 minuets to find.

 

[Slimshaddy]

Back before computer controlled engines that would be an easy find using the "bend, twist and tug" test on the wire harness.
Too many modern techs forget or never learned to give the wire harness a massage while monitoring ground and power readings.
The computers love to throw false codes and even create crazy ones when stuff like this happens.
Book learning only techs get ass kicked quick.

 

[leVieux]

Back before computer controlled engines that would be an easy find using the "bend, twist and tug" test on the wire harness.
Too many modern techs forget or never learned to give the wire harness a massage while monitoring ground and power readings.
The computers love to throw false codes and even create crazy ones when stuff like this happens.
Book learning only techs get ass kicked quick.

<>

We have seen this in Medical “Training” of young Physicians, too.

As a colleague once remarked: “When the electricity goes out, they become helpless!”

<>

 

[Slimshaddy]

<>

What I’m repeatedly hearing from the “factory-trained” dealer “technicians” lately is that, if the computer can’t diagnose the problem; there IS NO problem, no matter the failures to perform.

Mt brand-new JEEP stopped dead at 300 miles.

Report was “We can’t find anything wrong.”

“OK, start it up and let’s take a ride.”

“Well, it won’t start.”

”How in the Hell can you say there there is nothing wrong when the Dealer’s Shop can’t even start it?”

How confidence-inspiring !

leVieux

<>

You must understand that the onboard computer has ONE function only, it is to feed the catalytic converter/s a proper diet of partially combusted air and fuel, so that the converter can operate at the correct temperature to burn off pollutants.
The on board computer is not there to make more horsepower, although it does to that too, it is not there to act as an all knowing diagnostic guru to help service bay slaves.
Outside of monitoring sensor inputs, such as wheel speed, engine temp, mass airflow, manifold vacuum, throttle position, gear position, ambient temp, coolant temp etc...etc, the computer only recognizes opens and shorts in any particular circuit to set a trouble code UNLESS the problem causes increased tail pipe emissions, in which case the codes fly far and fast.
Bad connections, corroded terminals, wires almost completely, but not quite severed, restricted air filters, restricted fuel filters etc.. are out of the realm and beyond the programming in the computer so there can be a fault code that tells you there is too much un-burned fuel getting to the catalytic converter and it sets an O2 sensor code, but it does not have any way to know if an injector is leaking or if the air filter has a seagull stuck in it.
The O2 sensor is fine so changing it won't do a thing to prevent the code from coming back and that's where parts changers get in trouble.
Computers are magic and to wonderful things under the hood, but they are not smart.

 

[Brains]

Does it crank but not start, or does it not crank at all?

When you turn the key to the acc position, does the radio come on? Do the power windows work?

When you turn the key to the run position, does the dash light up, HVAC controls work, etc.?

I believe Otto is on the right track.

 

[TexasRedneck]

I'm gonna say check the grounds AND the main connections at the starter.....

'47 FORD w/a Chevy 350 crate engine. Ran like a striped-assed ape...until it shut down. NO power indications anywhere - alternator, accessory lighting - nada. Engine acted like someone turned the key off....which is essentially what was happening as it turns out. I was on Loop 410, center lane, on a Friday afternoon when this happened, so I was focused on getting to the side of the road before getting run over, so couldn't give him a GOOD report on symptoms, but I had a suspicion of a starter wiring issue. Letting the car sit for a few minutes would cause everything to be "good" again....but it would fail again, usually within minutes.

I'm not...ah...."svelte" enough to crawl under the car, so took it to a buddy's place. He found a bad/loose negative connection on the battery, and a couple of other loose/odd things, left it idle at his shop for an hour - and called it "cured".

I pick it up, get about 1/3 mile down the road, and it shuts down. NO power indications anywhere - alternator, accessory lighting - nada. That gave him the direction he needed, and sure enough, found a fusible link in the starter line that had been installed (poorly) with a butt connector that fell apart in his hands. We figure that there was JUST enough of a connection that it would operate properly when cold, but as it ran it would heat up and break the connection. Since that's been corrected, no further issues.

 

[Renegade]

My 2004 2500HD has been rock solid since new…until it died last month. 6.0L, automatic, 4X4, 160K. Idling in line at Walgreens and it flashed a bunch of idiot lights and the AC and radio quit. A few minutes later it started and ran fine to go home but would not crank once home. Serpentine belt is good. No alternator light but battery suggested I drove home without an alternator. Replaced the battery and it made no difference. Towed to shop. Shop billed a months’ retirement and said they replaced the PCB, whatever that is. Made one trip to town and it died three times in traffic in under 10 miles. Towed again! Mechanic has had it two weeks and cannot diagnose the cause. I’m going to have to have it towed somewhere else now.

Any of you ever seen this? I could sure use some guidance.

Have seen this on a 1990s Ford SUVs. It eventually was a recall/warranty issue known on "Thick Film Ignition". Basically it shut itself off as some wires or CPU overheated.

My Ford dealer told me it was fuel pump. Replaced ($500) and it shut off again 30 minutes after I picked it up. I found answer on BBS as it was not yet a recall issue. Back to Ford told him what it was, he called Detroit and it was fixed 2 days later. Would not refund my $500, saying well computer said it was the pump. Sold that POS and never bought a Ford again.

If not this, than go back to square 1 - Cars still work on same basic principles.

Spark, Fuel, Air.

Make sure it is getting spark at plug.

Make sure it is getting fuel in chamber.

Make sure air intake is not blocked.

 

[Slimshaddy]

If it fails to start/run then one of the above is missing.
Sparks at sea level require almost no amps, sparks in a hot combustion chamber require lots of amps, so look out with that one.
Checking for fuel in the chamber on a fuel injected engine is tricky too.
Blocked air intake, like blocked exhaust will allow the engine to run for one or two seconds before it starves for air or with a clogged exhaust, the inlet gets pressurized and stops moving air which puts out the fire.

 

[PhulesAu]

Mice maybe?

My F150 did the same thing out of the blue. Shop had it for a bit. They ended up reflashing the CPU. They said it lost its mind for some reason. They also said they have never seen that before in a f150

I have had several mechanics tell me that over the years.

 

[Dawico]

I've have plugs go bad on a few trucks over the years. Diagnosis says the part plugged in is bad but symptoms return on the new part.

Very hard to see a little burn on a plug but it fixed the issue twice now. $100 part but much more replacing what it plugs into first.

Good luck. Electrical gremlins can be a nightmare.

 

[cav2108541]

My 2004 2500HD has been rock solid since new…until it died last month. 6.0L, automatic, 4X4, 160K. Idling in line at Walgreens and it flashed a bunch of idiot lights and the AC and radio quit. A few minutes later it started and ran fine to go home but would not crank once home. Serpentine belt is good. No alternator light but battery suggested I drove home without an alternator. Replaced the battery and it made no difference. Towed to shop. Shop billed a months’ retirement and said they replaced the PCB, whatever that is. Made one trip to town and it died three times in traffic in under 10 miles. Towed again! Mechanic has had it two weeks and cannot diagnose the cause. I’m going to have to have it towed somewhere else now.

Any of you ever seen this? I could sure use some guidance.

Tow it to a used car dealer and sell it.