Engine/Transmission (1998.5 - 2002) Not charging, Stuck in gear

[jn14]

Have a 2001 24v 150,000 , was driving down the road the other day and quit charging. I got home pulled the alt off took and had it tested, checked out good (alt only a year old), load tested batteries and checked out good (batts new 12/1/11), so i put a ext voltage reg on, it fixed the charging issue but still seemed stuck in 3rd gear. Called neighbor whose big into cummins, he had a 01 pcm with auto trans, so i grabbed it off him and put it on removed ext regulator, fired the truck up and... ... no charging or shifting. Wondering what to check now? what wires to check? Any info please!



thanks in Advance

 

[cerberusiam]

Crank\cam sensor. That is what tells the ECU to allow charging.

 

[Sticks]

If the crank/cam sensor was bad, he'd get another code, or the truck would not run.

ECM does control the charging. Not a problem that I have encountered, but there is a way to test by bypassing the ECM controls - I can't remember how, hopefully someone will chime in with the in truck procedure. Odd that a second regulator installed cured it, must be something in the way you wired it in.

As for the stuck in 3rd gear... that may be mechanical since the second PCM did not fix it. ECM = engine controls/Alternator. PCM does everything else... Transmission. Check all the wires and connections to the transmission and check all the ground cables (more than 4).

I've got a feeling you have a bad ground somewhere that is the source of your issues.

 

[cerberusiam]

Probably are codes, doesn't look like he checked for them. Stuck in drive could be gov pressure sensor, solenoid, or output shaft speed sensor. ECM could be source of no charge, or grounds, or cable connections. With the particular problems it sounds like a missing signal from crank\cam sensor but that is a SWAG.

 

[jn14]

Checked codes, no codes present, both quit at exact same time, this is why it believes me not to be transducer or governer pressure solenoid, my vss sensor went out 10,000 ago (wouldn't shift out of first), like I said, cleaned batt cables, 2 quick connect cables on pass side next to battery, cleaned ground going from chassis to PCM, any other grounds to think of? Where are grounds from chassis to frame ( I haven't had time to look at truck), or any other ideas? FYI my tack and everything else works.

Thanks a lot in advance

 

[cerberusiam]

The charging is an ECM\PCM issue. I think the PCM controls charging on these trucks but I think it has to be activated by a signal from the ECM. That whole cicuit is a mish mash of stuff and might require and ECM to fix.

Possibly the same thing with the trans. 3rd gear starts are because the control circuit is seeing wheel speed that is not there or the solenoid is jammed. Hard to tell which one is the culprit because the PCM uses output shaft speed sensor readings and APPS postion to determine what the gear should be. No codes does not mean the sensors are good, just that the ECM does not see them as bad. About the only thing that doesn't apply there is rpm, it is seeing crank\cam sensor info because the tach is working. Whether the rest of the signals are getting to the PCM seems to be the issue.

You did check the trans relay to make sure it is hot and you have power on the trans connector harness? Limp mode usually sticks it in first but that is not a given on every single truck.

 

[Sticks]

I'm sure that there is a way to check this without one, but the only way I know how is to look at the downstream readings from a DRB III.

I'd put a call for help out to Jlandry, or move this to the 911 section.