Hey guys so this is my first post, I've been searching the Interweb for days/weeks trying to find a cause for my problem, hoping to get some help so here goes. Recently picked up this 2001 ram 2500 24v with a blown head gasket. I pulled the head, had it checked, cleaned everything and put it back together. Everything went great till i tried starting it. It will start, but as soon as its started it revs almost as if it was a run away. I can shut it down with the key so i know its not running away. I have my 5v at the apps, I've check the ecm pins all for power. Im not a electrical guru so I'm in desperate need of some help. Ive tried the apps reset with no avail. Hitting the pedal as its reving does nothing at all. I did write down all the pins on ecm that have power even the ones with very little volt readings (.01-3v) not sure if its a grounding issue or what is causing this. Ill try uploading a video of how it does when started. Any help is really appreciated. Thanks in advance.

I have you checked for codes? Was it running ok before the head gasket install?

4 minutes ago, dripley said:

I have you checked for codes? Was it running ok before the head gasket install?

Yes ive checked codes which are

P1693

P0113

P0237

P1488

P0122

I know one is for throttle/pedal sensor A circuit to low, but havent been able to find a clear answer to what is causing it. 

 

As far as running before the headgasket i have no clue. All ive done to the truck was the head gasket. The guy before me did all the parts. I bought it not running (no batteries) and just towed it to my house. Kinda dumb on my part, but its a not to rusted (living in michigan so everything rots). Plus i need something to haul our tractor and my little 1/2 ton chevy wasnt going to do it. 

I am not the electrical genius around here but it would seem there in issue with the 5v reference signal on the sensors. could even be a bad sensor causing trouble on the circuit. Others smarter than me will be along.

 

Here is a wiring diagram that will help.

 

 

 

7 minutes ago, dripley said:

I am not the electrical genius around here but it would seem there in issue with the 5v reference signal on the sensors. could even be a bad sensor causing trouble on the circuit. Others smarter than me will be along.

 

Here is a wiring diagram that will help.

 

 

 

Yes i was assuming it would be a bad ground or possibly a bad sensor causing this issue. Ive went over the grounds and made sure of good connections, check for power at the apps plug.  Im praying that it isnt the ecm that taken a crap. I will be testing a few of those sensors tomorrow and hopefully something will pan out. As far as the p1693 code, that i got from my scanner saying turbo circuit low. Not sure if that means anything. 

The 1693 is just one computer letting you know the other computer has a code in it. Nothing more.

I would be concerned with the P1488. Double check all your electrical connections for the batteries and ground make sure they are good. Then clear the errors and try again. If it returns then you might end up sending the ECM to Auto Computer Specialist.

1 hour ago, Mopar1973Man said:

I would be concerned with the P1488. Double check all your electrical connections for the batteries and ground make sure they are good. Then clear the errors and try again. If it returns then you might end up sending the ECM to Auto Computer Specialist.

Hi Mike,

               He bought it without Batteries.  Shouldn't he try the TPS calibration?  If it is bad, isn't there a TIMBO TPS in the store?

 

Thanks

Michael :- )

You can try a APPS reset...

 

I seriously doubt the APPS is the cause being the 5 volt signal is not being generated this makes ALL the sensors including the APPS wrong. First you need to fix the 5V problem before changing APPS sensors other than that you buying a APPS for nothing and still have the problem.

Thanks for the replies guys, i do have my 5v at the apps, a couple are a little lower in the 4v rage but im assuming its due to a bad ground. Ive also already tried the apps reset with no avail. Im hoping to have time later today to check a few other sensors for grounding out causing the lose of voltage. I was also told it could be a bad ecm causing the electrical nightmare. I did take readings from the ecm connector although im not sure which pins should have power with key on engine off. 

10 minutes ago, Squid said:

I did take readings from the not sure which pins should have power with key on engine off. 

 

Pin 5 is the key on signal.

4 hours ago, int3man said:

Hi Mike,

               He bought it without Batteries.  Shouldn't he try the TPS calibration?  If it is bad, isn't there a TIMBO TPS in the store?

 

Thanks

Michael :- )

I am not discounting what you say. It is a very good thing to try and might help. 

 

I just cant remember how many I have had my batteries disconnected and forget to do it. I never had it make a difference. But if I was having any issues, surging being on of them, it is simple to do just eliminate it as the issue. 

 

Not wanting to bring any bad luck but when did that it was the ECM. I was seeing alot more codes. There were both high and low codes for me. Hope yours is not the ECM.

Edited June 30, 20195 yr by dripley
added not to the first sentence

Pin 5 i have 12.29v as for the 5v which i believe is pin 3 and pin 10 i have nothing through the ecm Connecter. But im getting 5v at the apps with the ecm Connecter in. Not sure how that works. 

Pin 5 i have 12.29v as for the 5v which i believe is pin 3 and pin 10 i have nothing through the ecm Connecter. But im getting 5v at the apps with the ecm Connecter in. Not sure how that works. So far the pins with power are

pin 2 - 3.70v cummins bus (+)

pin 5 - 12.29v fused ignition

pin 8 - .01 manifold air pressure

pin 12 - 1.78v cummins bus (-)

pin 24 - .01v brake switch

pin 28 - 5.14v accelerator pedal position

pin 36 - .01v fuel injector pump relay control

pin 37 - 12.38v wait to start indicator

pin 39 - 4.23v sci receive

pin 40 - 2.46v ccd bus (-)

pin 41 - 2.48v ccd bus (+)

pin 43 - .02v vehicle speed sensor signal

pin 45 - 5.17v crank shaft position sensor

pin 48 - 12.38v fused b (+)

pin 50 - 12.38v fused b (+)

Some of the readings you take have to be made with the connector connected such as pin 3 and 10 since voltage comes from the ECM. The power for the ECM  comes from the connector. You can back probe them with a straight pin and then read them. Which other ones are like that I am not sure.

Since you had it part way down one thing that could cause it do runaway type deal is if the throttle cable is misplaced in the bracket.  DAMHIKT.  I would sure check and make sure it is seated correctly and square.   Hope this might be helpful for you or someone else in the future.

Alright ill back probe them and see what my readings are. Also when i did the head the wires from the map sensor pulled out of the connector. I thought i had them pushed in good enough but its possible there still loose or not getting good connection. I will double check that as well as far as the p1488 code goes. And for the throttle cable, i removed the entire throttle assembly and just set it off to the side. I didnt remove the cable or anything. 

They make straight pins with little plastic balls on the end. Keeps them from touching together if you have multiple back probes in a small area. 

Hey guys, I appreciate all the help. Sorry for the late response, things have been hectic with the holiday/work/kids. I did get time to mess with it. The guy before me had spliced the ground wire from the harness that connects to the APPS and but both ends went to the battery (essentially making one big loop through the battery). Well it made no sense to me when i did my head so i rewired the two cut ends back together when i did the head. I decided to rewire it back how the gentleman before me had it and a buddy held them to ground while i cranked it. Got it running and he removed the grounds and it idled fine. Touch one ground and itd speed up the rpms slow, touch the other ground and it would run away. So i also back probed the apps connector and only had 4.77v in one pin after being plugged in. Needless to say, i replaced the apps sensor and reinstalled the grounds how they were and she runs perfect now. No runaway, complete throttle control now. I appreciate the help and ideas/spots to look from yall. 

Good to hear.