ECM Swap Questions

[skid87]

Guys please excuse me as I am new to this platform. I recently purchased a 98.5 Ram 3500 5spd 4x4 that had some issues that I knew about before I bought it. It was throwing P0336 and P1693. Previous owner had replaced the crank sensor but I did it again just to be sure. Verified continuity from the ECM plug to the crank sensor connector  and installed a brand new connector also. It was still doing the same thing, start right up, run and idle fine but had no tachometer, and after about 45 mins to an hour start running very choppy and inconsistently. I swapped the ECM with one from a 1999 2500 5spd 4x4 suspecting it initially. The choppiness and bad running at the hour mark has stopped but I still have no tachometer and it just seems low on power.

 

Some other symptoms: random dead pedal for a second or two but always come back. Wait to start light seems somewhat inconsistent, for instance it wont do it every time you turn the key on. Idk if thats normal like if you just made it cycle it senses line pressure and does t turn on? Also has an aftermarket CD player in it, could it be improperly installed and putting RF interference into the collisiom buss? (This is all information that I have gathered over thr last few weeks, sorry if I sound dumb). Im suspecting VP44 computer failure? I also verified continuity from the ECM to FPCM. Any help or advice is greatly appreciated. Thanks 

[Me78569]

sounds like someone swapped a 01-02 engine into your truck.  I would verify what engine your truck has 1st

[skid87]

37 minutes ago, Me78569 said:

sounds like someone swapped a 01-02 engine into your truck.  I would verify what engine your truck has 1st

How would I be able to tell? It has a crankshaft position sensor in it.

[Me78569]

look at the number plate on the engine. 

[syndicateshop]

Stick your finger in the cam position sensor hole, is there a tone wheel? That will tell you which iteration. All 24v have crank position sensors. Just depends where it is, 98.5-2000 are actually on the crank, 01-02 is in the timing case. Ask me how I know........

Edited August 2, 2018 by syndicateshop

[dripley]

My 02 does not have a crank sensor only a cam sensor in the timing case.

 

I also thought, my 02 anyway, that the cam sensor read from a notch in the cam gear and not tone wheel. I don't remember seeing one when I opened my gear case a few months back.

[syndicateshop]

@dripley the schematics and Cummins call the sensor a crank sensor. In the01-02 harness the same pins are utilized as the crank sensor from the 98.5-00 ecm. There is no listing for a cam sensor in 01-02. In fact the truck I'm driving right now is a 98.5 with an 01 ecm/engine using a 98.5 harness. I had to make an extension cable to extend the crank sensor plug to reach the timing case.

Also the cam gear now has provisions to bolt the tone wheel to it where 98.5-00 cam gears just have a notch.

[dripley]

2 hours ago, syndicateshop said:

@dripley the schematics and Cummins call the sensor a crank sensor. In the01-02 harness the same pins are utilized as the crank sensor from the 98.5-00 ecm. There is no listing for a cam sensor in 01-02. In fact the truck I'm driving right now is a 98.5 with an 01 ecm/engine using a 98.5 harness. I had to make an extension cable to extend the crank sensor plug to reach the timing case.

Also the cam gear now has provisions to bolt the tone wheel to it where 98.5-00 cam gears just have a notch.

Appreciate the info it seems I have backwards. I guess you cant see a tone ring from the front. There does appear to be some bolts screwed in from the back though.

 I know when I bought a replacement sensor it was listed as a cam sensor and the wiring diagrams call it a cam sensor. It did not come from Cummins however. Though the trouble codes list it as a CKP I believe. 

 My education continues.

[syndicateshop]

@dripley no problem, it's nice to do the teaching once in a while.