2001 Dodge Ram 3500 5.9 cummins diesel.  I have code po501 and after thinking back this Code started right after I changed my tires from 31inches tall to 35inches tall.  I did any way check ABS Sensor/Replaced anyway. VSS/Replaced it anyway. Apps sweep test, test perfectly Replaed it anyway.  So I am back to It has to be a programming issue with the ecm/pcm.  I had dealership inter in the correct tire size and set the RPM's @800.  Gps we will say shows 71mph when the dash speedometer reads almost 69-70mph.  Is there a different setting the dealership should be doing also? 

Read up on this...

 

Monitor & Set Conditions

Vehicle Speed Sensor (VSS) signal is monitored when no VSS DTCs or Chrysler Collision Detection (CCD) errors are set. DTC may be stored when CCD vehicle speed indicates greater than 20 MPH for 2 seconds, ECM vehicle speed indicates less than 10 MPH and PCM does not receive a VSSsignal from Controller Anti-Lock Brake (CAB) module.

 

My first though is to check for excessive AC voltage from the alternator. If there is excessive AC noise it could be fouling the CCD network and the computers are not seeing the speed signal correctly. 

I just checked the Alternator with the truck running.  It has 13.78 volts and it starts out at .3 vac and slowly drops to .15 vac.  Does that sound Good to you Mike?  All of a sudden I'm getting a bad whinning noise under the dash by the steering column, what is the module do?

Should I test VAC while revving the engine upto 1600rpm's or so.   This whinning noise is not there until 1300rpm when on the gas driving.  It does not make noise in the driveway.  Any help would be great.

I took Alternator in to have it bench tested, Diodes Passed,Both Batteries Passes.  I was really hoping it would have bad alternator due to the crazy whinning noise coming under the dash when over 1500 rpms.  Check Grounds Cleaned Batter Cables again.  

the whinning noise is possibly the torque converter???

7 hours ago, CLAUS1 said:

It has 13.78 volts and it starts out at .3 vac and slowly drops to .15 vac.  Does that sound Good to you Mike?  All of a sudden I'm getting a bad whinning noise under the dash by the steering column, what is the module do?

 

 

Very bad... Normally good alternator is 0.01 to 0.03 AC volts. Diodes are cooked and the alternator is junk.

 

 

I just put a Brand New Alternator on the truck and tested the New Alt. VAC.  With the truck Running it shows .05 vac with all accessories turned off or unhooked.  According to the video and your numbers the New Alt. is BAD?  

Marginal... Is it New or reman'ed? I always test my alternator before I leave the store.

I did have them test it. It was reman.  It showed , -.11 on my bench. Led on post and other at base ground. 

0.01 to 0.03 is normal.

0.05 is marginal.

0.10 is failing.

 

Remember these numbers are for the home test. Bench test machine is going test under full load. So be careful I need to know what method you used.

I tested the positive wire while the truck was running at the back of the alternator with the neg- on the battery.  Should I test it different?  The tranny is still ating up in/out of 3rd 4th lock up and unlock even with the overdrive switch off it will sometimes kick in/out of 3rd lockup

 

Sounds like a bad alternator.

On 2/2/2017 at 7:30 PM, CLAUS1 said:

I tested the positive wire while the truck was running at the back of the alternator with the neg- on the battery.  Should I test it different?  The tranny is still ating up in/out of 3rd 4th lock up and unlock even with the overdrive switch off it will sometimes kick in/out of 3rd lockup

 

 

 

On 2/2/2017 at 3:42 PM, Mopar1973Man said:

 

0.01 to 0.03 is normal.

0.05 is marginal.

0.10 is failing

 

 

 

Here is my video on it...

 

I did pull the connector off the alternator and pull out the 140amp alternator fuse. Drove the truck around for 30 minutes,pull the fuse and connector did not change the way the tranny shifted at all.  I felt I've checked all i can check without DR111/scan tool.  So I took it to dealership today and had them put the tires to 601rpm rather than 800rpm, the tranny did shift better but the 501 code is still there.  Dealership ran test for 4 hours will I waited to see what they think?  They told me he believes its the CAB Module but not sure, he is waiting for "Dodge" to respond to with some input.  He did take freeze frames data  and sent it off to them.  What does the CAB Module exactly run?  Is that the box under the left side of the dashboard that I'm all of a sudden hearing squeling? Dealer didn't charge me but they are Really Scratching there heads

New ECM fixed the p0501 and p0500 code the truck was getting.  Was not CAB module like dealership thought!

New ecm did? Weird as it does not deal with vehicle speed messages.

Yes, Just New ECM.  I called Computer Resource Company they said yes 501 code could be caused by broken/solder joints on the board.  501 could would come on after driving 25ft every time.  501 code has not come on again!