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 Dodgerench Your Own Question
Dodgerench
Dodgerench, ASE Certified Technician
Category: Dodge
Satisfied Customers: 3385
Experience:  30+ years Dodge/Chrysler exp., ASE Master with L1 certification. Driveability/ combustion specialist
4486286
Type Your Dodge Question Here...
Dodgerench is online now
A new question is answered every 9 seconds

03 ram quit going down the ghway starts runa thens stalls

Customer Question

03 ram quit going down the highway starts runa thens stalls intermittent run and quits
Submitted: 11 months ago.
Category: Dodge
Expert:  Dodgerench replied 11 months ago.

Hi, welcome to JustAnswer!. This is Ed.

Have you been able to scan the engine controller for codes yet? I ask because I'm looking for a reason for your throttle position sensor replacement (was it code-directed?).

If you have no access to a scan tool, the 3.7 and 4.7 Ram truck support a customer code-read feature. Hemi may not be supported.

Roll the key from off to on three times, leaving the key ON after the last cycle.

Watch the instrument cluster in the odometer area and if codes are present, they should be shown.

Talk shortly,

Ed

Customer: replied 11 months ago.
No codes acted like fuel pump but have tested it. Shows 48 psi all day. Tps was an educated guess considering all I've researched and read that being said problem still exists could the fuse block be the issue? Have read many problems about this
Customer: replied 11 months ago.
Or possibly cam/crank sensor is bad again? Seems to happen when vehicle reaches operating temp. Acts like its bad fuel??!!!
Expert:  Dodgerench replied 11 months ago.

With no codes, I'm at first inclined to think that your problem isn't a monitored failure, something like fuel pressure. Are you sure that pressure never drops when it acts up? If it shows 48 PSI when not running, we can certainly dismiss that possibility.

Engine size, please?

Customer: replied 11 months ago.
4.7 liter bought a fuel pres. Tester shows 48 psi all day fuel pump does come on can hear it. Truck will run run just won't stay running when the accelerator is pressed but as I have said its intermittent. I'm scratching my head on this one all symptoms lead me to believe it was fuel pump.
Customer: replied 11 months ago.
Also a few years back I replaced the ignition switch plug that connects to the back of the assembly I pulled that connection off and have found the top two wires in that bank are blackened is this possible???? Lack of ignition due to a short in this plug???
Expert:  Dodgerench replied 11 months ago.

If you can positively verify that you have normal fuel system pressure during one of these events, it eliminates the fuel pump. Just the pump -- not the stuff in the tank, but chances are slim that you have a water problem with the randomness that it shows itself.

Losing power to the PCM is a very real possibility, given the description of your ignition switch connector. Loss of power would be treated the same as a key-off event, certainly not a reason to set a code of any kind. By all means take another look at your connector and let me know if any terminals appear suspicious and their wire color. Number-wise, the factory identifies terminal position with the connector open end facing you, with the slide-lock pointed up. The left vertical row is 1-7 and the right is 8-14, top to bottom.

I checked for electrical-type recalls for your 2003, but didn't find any. We relocated the blower motor switch feed in '02, but it doesn't apply on your unit.

This was a changeover model year for engine controller types as well. You may have a JTEC or an NGC unit, each of which have their own personalities. If you get near the truck, pop the hood and count the number of connectors at your PCM, located over near the passenger side hood hinge. It'll be either 3 or 4 connectors on a metal box measuring roughly 10"x6", held to the firewall with three 8mm screws (for either). Thanks.

Customer: replied 11 months ago.
the number 8 connection is a green wire thru thr splice back to the original and has some blackening at the wiring on the back side of the plug connector. the pcm is a 4 connection unit silver box 10x 6 says its a motorola unit i will take pics and respond from my phone next
Expert:  Dodgerench replied 11 months ago.

Oooo. Blackening of the wire? That shows some serious resistance and heat buildup. Hang on and I'll trace out the circuit.

Customer: replied 11 months ago.
Photos
Expert:  Dodgerench replied 11 months ago.

No bueno. This is the same heater blower motor feed that we moved out of the switch back in 2002. Sadly, its only job is to push air around the cab.

Yep, that's an NGC controller and I surely appreciate the picture of your switch connector. We're gonna have to keep looking, unfortunately.

Customer: replied 11 months ago.
this issue isnt indictive of the problem its just the blower motor power source
could the pcm possibly be bad
what happened when this all occured i was on the expressway and the road crews were laying down a liquid solution in which my truck was covered in thats when this event happened that being said i have incurred some engine lights prior but it reset itself prior to me checking for codes that being said within the last year or so i have had numerous misfire codes only for on a few occasions to replace a bad coil 3 times to be exact always solved the problem this issue is not blowing any codes
Expert:  Dodgerench replied 11 months ago.

Yep, it's just a blower motor power source and nothing else. Looks like somebody didn't learn their lesson in 2002.

The PCM could be bad, but it's pretty rare for an NGC unit to die intermittently -- or at all for that matter (that was JTEC's job).

The NGC controller has one quality that JtEC didn't have; that it doesn't become unconscious if the 5v feed to cam, crank, MAP, TPS is shorted to ground. The engine will still likely die, but a trouble code or ten should be generated and it'll remember it. JTECs just take a nap and wake up wondering what happened.

So, with no codes stored and fuel pressure good, my speculation machine is running low.

Can you describe what it feels like when your truck dies out?

Sudden stall?

Or more gradual, as if you were losing the fuel pump (as you described).

Is it a linear drop to nothingness? Or does it recover and retreat?

Does it matter how much throttle you give it? Like... does it improve or get worse with more throttle?

Customer: replied 11 months ago.
when it runs and i drive it i try to put acceleration to the vehicle and it either goes or quits as i said its intermittent that being said when its cold it will run all day reach operation temp and its more evident but that just an observation at this point
im still wondering if ay of that road debris got up into the fuse block assembly as it is vulnerable to road debris and water etc etc etc etc
as im recalling driving thru deep puddles of water the vehicle has stopped on me on occasions but has refired and gone on about its business could it be there is a short in the board under the fuse block area ???????
Expert:  Dodgerench replied 11 months ago.

Well... now that you mention it...

Yes, the fuse block is open from below and has suffered from corrosive damage in some markets, like ones where road crews spray liquid death. There just isn't anything in there that I'd expect to be momentarily sensitive to spray, but it's hard to discount the coincidence of what you saw. We see loss of park lamps fairly often with these fuse blocks/ IPMs as road salt eats away at a printed circuit board, but nothing else that I can recall. The ON-OFF (either running or not) feel you described when it's dying out does sound electrical to me.

Another low-lying place on the 4.7 engine is the crank sensor on the lower right engine block and you probably already know that. You might try selectively spraying the truck down to see if you can get a reaction of some sort. Start low because water runs downhill and you might test too much area at once by spraying the top side first.

Customer: replied 11 months ago.
that fuse block does come apart correct ??? in order to get to the circuit boards underneath ? and yes cam crank sensor has been replaced once brother had the same issue with his intrepid several times but no code thats whats boggling me here no codes last time it went out on me i had a code
Expert:  Dodgerench replied 11 months ago.

That's the part that's causing me trouble too -- no codes, yet something serious enough to kill the engine is happening.

The fuse block does come apart, but unless you can wet the thing down and cause a reaction I wouldn't worry about it.

Do you have your fuel pressure gauge mounted where you can see it while driving? What I'm concerned about is whether you were able to catch the engine in its dead state while monitoring the fuel pressure.

Expert:  Dodgerench replied 11 months ago.

There's a connector that sits right behind the LF wheel well that gets lots of abuse from road debris and water that feeds power and ground to the fuel pump. But of course, that means your pressure drops.

Customer: replied 11 months ago.
well at the point of fuel pressure testing i wasnt driving the vehicle but just puttering in the yard back and forth under load even in the stalled failed state the pump is reading pressure and any givin state but will try again
Customer: replied 11 months ago.
the fuel pressure when in running state did fluctuate a cple pounds but i dont think it was major drop or spike in fuel pressure a cple # ***** in other words the needle did move but nothing major like 5# ***** fluctuation
Customer: replied 11 months ago.
where exactly is this connector
Expert:  Dodgerench replied 11 months ago.

Thanks. Pressure will drop slightly when the engine quits turning, so that's normal. The important thing is that you had most of your pressure left over so I feel better about ruling the fuel delivery system out.

It's directly to the rear of the LF wheel, behind the splash shield. You'll see it if you slide in from underneath. It comes apart hard due to all the road crud that accumulates in the release mechanism, so shooting it with water and compressed air is sometimes needed to get it apart.

Expert:  Dodgerench replied 11 months ago.

Check this for me.

I've seen wiring harnesses rub on the sharp corner of the passenger side cylinder head back where you can't see it. Start the engine and lightly tug, push, wiggle the big section of harness that disappears to the back side of the engine. Use more and more amplitude in your manipulation as time passes, but at first be gentle with it to prevent the loom from becoming repositioned. If you move it too much, you risk losing the exact rub condition that may be present and while it means the truck won't break down again soon, it will break down again at some time. Feel free to wiggle test your wiring anyplace you find it (like near the PCM and metal A/C lines) to see if something acts up.

Customer: replied 11 months ago.
Won't stay running long enough
Expert:  Dodgerench replied 11 months ago.

It's dying out now? Now?

Got a voltmeter?

Check the orange wire at your TPS. It's shared with the crank sensor and should be right about 5.0 volts.

Expert:  Dodgerench replied 11 months ago.

I thought it was intermittent. So it's acting up all the time?

Feel free to recheck codes.

Customer: replied 11 months ago.
i do have a voltmeter but how do i check the wiring while its still hooked up
Expert:  Dodgerench replied 11 months ago.

You can push the test terminal in through the rubber weatherpack at the end of the wire where it enters the connector or use a paper clip to probe it.

Use the 20 volt DC scale.

Customer: replied 11 months ago.
no codes again no engine light it will start then stall run for a few minutes then stall restart again same situation
Customer: replied 11 months ago.
ok brb
Expert:  Dodgerench replied 11 months ago.

Interesting. Let's set a code and see if it stays there after it stalls.

Go ahead and disconnect your TPS connector with the key on and take your reading. This will set a P0123 code.

Then reconnect and start the engine. After it dies out and will restart, recheck for the code. If it disappeared, the PCM is quite possibly the problem.

Customer: replied 11 months ago.
i got volts on the orange
Customer: replied 11 months ago.
i got 5 volts on the orange
Expert:  Dodgerench replied 11 months ago.

That's good.

Now check to see if you have the P0123 code stored. Disconnect the TPS if you haven't already done so and it'll set.

Customer: replied 11 months ago.
i dont have my code reader at the moment it just left for a few moments
Expert:  Dodgerench replied 11 months ago.

You can use the key switch method.

Expert:  Dodgerench replied 11 months ago.

Key on, off, on, off, on. Watch the odometer for code display.

Customer: replied 11 months ago.
po113 po123
Customer: replied 11 months ago.
forgot about that
Expert:  Dodgerench replied 11 months ago.

Good. Now start the engine and run it until it quits again. As soon as it'll restart, recheck codes.

Customer: replied 11 months ago.
Says done
Expert:  Dodgerench replied 11 months ago.

All the codes disappeared?

Customer: replied 11 months ago.
Expert:  Dodgerench replied 11 months ago.

Wow. Not expected, but it does explain some stuff.

Now all we need to do is to check powers and grounds on the PCM C1 connector to be sure they're good. After that, it's lights-out for the PCM. I didn't see that coming.

Expert:  Dodgerench replied 11 months ago.

The C1 is your top connector as seen in the picture you sent. A red slide-lock has to be pulled backward to enable the thumb tab release.

Customer: replied 11 months ago.
OK I'm there disconnected
Expert:  Dodgerench replied 11 months ago.

Terminals are arranged kind of backward on these connectors.

Roll the connector so the terminals face you and the release tab is UP.

The rows are numbered from right to left.

The top row is 1-10, next is 11-19, etc.

Customer: replied 11 months ago.
Ok
Expert:  Dodgerench replied 11 months ago.

Grounds are terminals 9 and 18.

Power sources are...

11 and 12 being key-on feeds. Wakeup calls. I don't believe we'd have a problem with either of these because if lost, they'd just shut the engine off but no memory would be lost.

29 is your B+ (battery) feed. We're probably going to need to load test it.

Expert:  Dodgerench replied 11 months ago.

Do you have a common 12v test light? The one with a bulb in the handle?

Use it to load test your Pin29 power source and the 9 and 18 grounds. It's not much of a load, but a bulb does draw a little power.

Customer: replied 11 months ago.
No I don't have one
Expert:  Dodgerench replied 11 months ago.

My preference is to build a load tester out of a fog or headlamp bulb. They draw about 4 amps which is plenty to root out power or ground supply problems.

Plus brightness of the bulb tells you how much current is flowing.

Expert:  Dodgerench replied 11 months ago.

Dang. I know this is inconvenient.

Expert:  Dodgerench replied 11 months ago.

But that's about where we're headed. You either have a weak power or ground to the PCM or a bad PCM. A good load test of those three circuits would be the decider.

Expert:  Dodgerench replied 11 months ago.

Can you think of some sort of 12v appliance you might have around?

Customer: replied 11 months ago.
Here's the pic
Expert:  Dodgerench replied 11 months ago.

It could be a motor or about anything that runs on 12 volts and can be wired up like a test light.

Oh, MY. That connector did get hot.

But that's all switched power and I don't think we necessarily have a problem with that at the PCM.

What does the ignition switch look like?

Customer: replied 11 months ago.
what do you mean?? how does the switch look
Expert:  Dodgerench replied 11 months ago.

Is it all charred like the connector?

Customer: replied 11 months ago.
are we going to test this at this connection ?
Customer: replied 11 months ago.
i have a light on the way
Expert:  Dodgerench replied 11 months ago.

All I'm really interested in right now are the three terminals at the PCM. 9, 18 and 29.

Light? Good.

I do have to leave very soon, so we may have to take this up again later. Emergency at the IL's.

Customer: replied 11 months ago.
i understand its gonna be a little bit for me so what im curious is are we testing the pcm or the ignition switch ??
Customer: replied 11 months ago.
ok i gotcha we are on the pcm which i have to disconnect im sorry
Expert:  Dodgerench replied 11 months ago.

Yep. Be careful to avoid stuffing anything into the open terminal ends. Just stick with the outside surface to avoid spreading the contacts.

Customer: replied 11 months ago.
ok gotcha better deal with your inlaws ill shout back at ya
Expert:  Dodgerench replied 11 months ago.

Thanks for your understanding. See you in a bit.

Customer: replied 11 months ago.
I have test light and are ready whenever you are
Customer: replied 11 months ago.
i will let you know this i have to go out of town for work as of tomarrow and will be gone a week so if we dont reconnect tonight im hoping we can when i get back
Customer: replied 11 months ago.
i am prepared with a test light and the plug is disconnected i checked all legs that you were concerned with and got no light
Expert:  Dodgerench replied 11 months ago.

Pin 29 is the battery power source to the PCM. It's the far right one in the fourth row. It should light if your test light alligator clip is connected to a good ground source. Power comes from Fuse 19 (20 amp) under the hood. It would be a good idea to pull the fuse and check for discoloration or looseness of pins.

Key on sources are Pins 11 and 12, should light the test light with key on only.

Pins 9 and 18 are grounds, so you have to switch your alligator clip to battery positive to test them. The grounding lug is on the passenger side-rear of the inner fender. You'll see a bunch of ground wires all connected under one bolt.

Leave the test light on any terminal you want to test for a bit and even do some harness wiggling if it doesn't seem to be OK. Watch for intensity change in the bulb.

Gotta run again, see you later.

Customer: replied 11 months ago.
29 gets light all day no issue there 11 and 12 test fine with wiggling to the harness 9 and 8 to positive is all good its getting dark here and temp is dropping im headed to buffalo for a week respond with your thoughts please
Expert:  Dodgerench replied 11 months ago.

You'll probably get snowed on.

Well... you asked.

The way I see it, you need a PCM. The engine shuts off suddenly, never sets codes, holds fuel pressure, has good power and ground supply AND loses memory between events. It's the loss of memory that clinches it for me.

PCM condemnation comes slowly and is mostly a game of attrition. Once you've eliminated everything else, that's when I have to pull the trigger.

If you go with a factory unit, you'll need to have someone program it to your truck. if you happen to have the grey ignition key -- the one with the immobilizer chip -- the truck won't even start until programmed.

Aftermarket sources can program a PCM for you remotely so it starts and runs as soon as you plug it in and they're usually cheaper. I can't attest to their quality, but they usually have a liberal exchange policy if the new one has problems (which they often do).

Try to enjoy your trip (shuffle?) and feel free to rate our experience any time you like. I'll always be there for followup.

Take care,

Ed

Customer: replied 11 months ago.
No grey key with a chip so should I outsource a pcm? Junkyard or aftermarket ? Prolly will get snowed in out there lmfao and drive my work vehicle home BTW which is a Chevrolet 2500 utility lol
Expert:  Dodgerench replied 11 months ago.

I think you'll probably have to go with a commercially remanufactured unit, either Mopar or aftermarket. Since you don't have the SKIM immobilizer, introducing a controller that had SKIM in its previous life isn't possible. You can do it with one that did NOT have SKIM, but junkyard controllers all look alike and I'd place odds at 50/50 to get one that is usable. SKIM is a programmed feature and can be present or not present on the exact same part number, so you can't tell anything by reading the label.

Yeah, go with whatever you feel comfortable with. Aftermarket is definitely easier.

Customer: replied 11 months ago.
Definitely the cheaper option aftermarket. Around 200 $ pre programed
Expert:  Dodgerench replied 11 months ago.

That'll work. The key is to remember what your original problem was and to not accept new stuff. If the new controller comes with extra trouble code baggage or if it still dies, but it's different in how it is stalling, you imported someone else's problem. Return it and try another one.

Customer: replied 11 months ago.
OK thank you sir
Customer: replied 11 months ago.
Will report back when I replace might be a week or so!!!!!
Expert:  Dodgerench replied 11 months ago.

Sounds good. Remember, in an avalanche, stay in your vehicle.

Ed

Expert:  Dodgerench replied 11 months ago.

Oh crap, who would actually predict snow in BUFFALO in the winter? Lottery odds!