Motor is FREAKIN' out! Truck dead. Please help!

4x4dually

4x4dually

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Wow. What a way to finish a Monday. Here's the scoop.

Chapter one:
Come out of work and start the truck. It is about 40F and I pull right out and don't let it warm up any. I get two blocks and I start getting a dead pedal off and on like the IP is going out once I back off the pedal at the speed limit. I thought I could make it home which was another 20 miles, but after about 5 miles it loses all power pulling hills and starts this reving up and down reguardless of what my pedal is doing. I then get a check gauges light and look at my temp gauge. The SOB is pegged past 240F! I then pull off the road and think "this can't be right, I've driven 10 miles in 40F weather the dang thing can't be over-heated". So I stick my finger in the coolant, warm, but just being in proximity to the engine heat warm, it should have burned my finger off at that temp. I figure it was a themostat and it just thinks it is hot and is shutting down.

Chapter two:
I notice the edge is reading Engine Coolant Temp to be 188F and the dash is reading 240 then 180 then 200 then 240 back and forth while it idles. All other gauges are good, volts, fuel, oil pressure. The edge reads 188 constant and the dash wigs out. Then I thought I'd un plug the temp sensor by the thermostat and that didn't change anything.

Chapter three:
Then I get the smart idea to read the codes. That was my final mistake. Now I'm worried sick.

P1693
DTC Detected In ECM Or PCM

P0121
Accelerator Pedal Position Sensor Signal Volts Do Not Agree w/Idle Validation Signal

P0238
MAP Sensor Voltage Too High
P0563
Charging System Voltage Too Low

P0113
Intake Air Temperature Sensor Voltage High

P0118
ECT Sensor Voltage Too High

P0577
Cruise Ctrl Input Circ Hi

P0343
Camshaft Pos Sensor Circ Hi Input

P0123
Accelerator Pedal Position Sensor Signal Voltage Too High


WTF could cause all these? I have trouble seeing a single point of failure here. I wonder if an entire harness has come unplugged? I had no time to really work on it last night other than taking the thermostat out so I could get a new one today. I'd like to get some opinions on where to start when I get home. The thermostat does have something loose in it. I can shake it and it rattles. I don't know if that is normal, I doubt it, but don't know.

Sorry for the long read...it was only a small fraction of my evening and a portion of the cuss words! :D
 
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Did your alternator fuse blow, mine did and couldn't figure out what was the matter and it was doing al kinds of crazy stuff, it's the big 140 fuse
 
It gradually got worse so I wouldn't think it would be a fuse, but after seeing all the codes, it has to be electrical. Dodge just told me the thermostat was $84.00!!! (NAPA $23.00 with seals, 190F). Are they smokin' crack? Cheese and Rice that's ridiculous! If I go after market what temp would you recommend? The Dodge lady couldn't even tell me what temp the stock one was. :bang

I'll check fuses tonight and put a new stat in her. Hopefully that will cure it. There has to be some ting wong.....
 
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4x4dually said:
It gradually got worse so I wouldn't think it would be a fuse, but after seeing all the codes, it has to be electrical. Dodge just told me the thermostat was $84.00!!! Are they smokin' crack? Cheese and Rice that's ridiculous! If I go after market what temp would you recommend? The Dodge lady couldn't even tell me what temp the stock one was. :bang

I'll check fuses tonight and put a new stat in her. Hopefully that will cure it. There has to be some ting wong.....
Click to expand...

Yeah if the alternator fuse blows it will not be able to keep the batterys charged and your ECM will gradually lose power doing crazy stuff like that then eventually die.
 
dzlfarmboy said:
Yeah if the alternator fuse blows it will not be able to keep the batterys charged and your ECM will gradually lose power doing crazy stuff like that then eventually die.
Click to expand...

But.... the alternator guage was reading 14V the whole time. I'm on board with the ECM taking a big ol' corn infested load right there on highway 51. I sure hope not.

I have been getting a flutuating pedal with the cruise set on downhill coast like the IP did when it went out 50K miles ago. I sure hope not.

I'll put a new stat, check fuses, and read some voltages tonight and see if I can't get her running. It would idle on its own but it would run to 2K and back down..back and forth...I guess that is what it does when the APS is hosed!

You know I called a dodge to pull me home...wasn't going to be seen pushing a Ford or Chevy! :hehe:

Am I going to need a code reader to clear codes when I get it fixed (whatever it is)? Someone told me it could be in limp mode due to the overtemp. How the hell do I get it out of limp mode? I hate it when it goes limp.
 
DAMN i though i was mad when my window switch quit and i couldnt roll up the window(but i finally did) last night on the way home. jory i got the hypertech still that can read the codes and clear them if you need it. and if you need any help just give me a shout
 
4x4dually said:
But.... the alternator guage was reading 14V the whole time. I'm on board with the ECM taking a big ol' corn infested load right there on highway 51. I sure hope not.

I have been getting a flutuating pedal with the cruise set on downhill coast like the IP did when it went out 50K miles ago. I sure hope not.

I'll put a new stat, check fuses, and read some voltages tonight and see if I can't get her running. It would idle on its own but it would run to 2K and back down..back and forth...I guess that is what it does when the APS is hosed!

You know I called a dodge to pull me home...wasn't going to be seen pushing a Ford or Chevy! :hehe:

Am I going to need a code reader to clear codes when I get it fixed (whatever it is)? Someone told me it could be in limp mode due to the overtemp. How the hell do I get it out of limp mode? I hate it when it goes limp.
Click to expand...

Put the whiskey bottle down....:hehe: :hehe: :hehe: :hehe: :hehe: :hehe: :hehe:
 
OK, couple of items.

Check all the plugs on the harness and look over the whole thing for any broken/chaffing wires. You have already checked fuses, but did you check them with a meter for continuity or just look at them?

To clear all the codes remove all battery terminals and then touch the positive and negative cables together for at least 30 seconds, this will drain the capacitors in the PCM and get you back to a "clean slate" in the computer.

FWIW I think you have a fried PCM, not ECM.
 
O God Billy, how much is that gonna cost me? :hehe:
Got one layin' around? :poke: I'd drive to all the way down there to buy you a steak if it also fixes my surging problem! :D

I'll defineatly get the DMM out tonight and do some probin'. I did the "drop the thermostat in a cup of boiling water" a little while ago and it don't open. That has to be one problem. Can the overtemp cause any of this? Sound hookie to me!
 
I don't think it overtemped Jory, the temp probe is located on the the T stat housing which always has a little bit of flow through it, if the temps are reading 188 at the Edge, and 240 at the gauge, and they are both getting their signal from the same source your problem is likely in the PCM. IIRC the temp sensor signal is sent from the sending unit, to the PCM, the PCM then sends a signal to the actual gauge. Now if there is a ground problem (as Forrest pointed out) the resistance based signal it's looking for would be wonky, especially if the ground issue was intermittent. Matter of fact the more I think about you cleaning connections and getting it back going the more I have to agree with Forrest and say bad ground, or at least a bad connection somewhere.

If you do wind up getting a PCM go to the dealer or one of the online parts discounters, getting one used is a crap shoot and not worth it IMHO. I bought one 3 years ago for $250 and change.
 
Rookie question: Where is the PCM? :bang Box under the center of the dash on the floor?
 
Passenger side firewall, if you pull your air cleaner out that box you see with all the wires coming out of it? That's the PCM, the ECM is located on the side of the block.
 
when a 24v truck comes into HotRodDiesel displaying odd drivability issues, the FIRST thing that happens is all grounds are checked/cleaned and some of the factory connectors are cut and replaced with a permanent soldered connection.

I think we got spoiled with the 1st and 2nd gen 12v's... almost 10yrs of simple mechanical injection and the 24v's are much more sensitive to bad grounds/connections with all there electric sensors and an ECM that has to interpret the signals. And a lot of people's instinct is to look at the ECM and sensors, but without good grounds/connections, those little electric do-dads can't do their job!

seen a fair amount of this kind of thing solved w/ new grounds
 
I agree. Bad grounds kill stuff. Any ground points in particular that I should check first other than the obvious batter posts and engine grounds?
 
I had my truck cut off on me going down the interstate one day. I was advised to clean all my grounds and it hasn't happened since. I got at least eight electrical codes when this happened too. Luckily I was on my way to TRE when it happened.

Don't forget the one between the cab and the bed =P
 
Unplugged ECM. Checked all grounds to battery they all read good. Also checked +12 VDC input to ECM. 12.04 with truck off. Also read +5 VDC sensor output lines and they read good. So, ground and power to ECM are all good. Truck lopes back and forth from idle to 2 grand when started and not touching anything. New stat and temp probe tested with a heat gun. Cold 13K ohms hot 2K ohms.

Hurst.....KMA!!!! :D

I guess I can take it to dodge or cummins and they can test the ECM and PCM and tell me if they are bad? Maybe the ECM needs a reflash? I'm stuck. No ideas. I'm in between a rock and a place where my truck don't run. Everytime I start it, it runs worse and lopes more.

WTFFFFFF??????
 
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