Back in July I lost ECM output for my lift pump.  I tested for AC noise at that time and had no issue so I corrected and added a fused power source and now it runs off a switch.   BTW alternator is believed to have the same milage as the chassis which is 332,732

Two weeks ago to transmission started having issues with torque converter clutch lock up it was hunting a lot.  I threw a scanner on it and started collecting live data.

I find out my accelerator pedal position sensor will not register over 80% at wide open throttle.  At this point I was very confused so I started testing more things including A/C noise again and the alternator is still fine my batteries are fully charged and the app sensor is a 2 years old Mopar unit.  I have recalibrated the sensor as well as removing battery cables over night.

By the way my alternator putting out .01 volts ac occasionally it goes to .02 on the meter.

Where do I go next how can I bench test the sensor it's self, then are the transmission problems from this sensor or something else?  

I've got to ask how are you testing the AC noise at the back of the alternator or at the batteries? Also what brand of meter are you using? What setting are you using on the meter to do the testing?

 

Just seems odd you've got the hunting problem but no AC noise... APPS sensor will not cause hunting issues. I would consider a Timbo's APPS before another Mopar or stock APPS sensor again.

My alternator is barely under the marginal acceptable level for A/C noise, so whenever I need to clean battery posts the hunting always tells me when it needs doing again. About every three months or so. Once I only retightened batt cables and it went away for a week or so, but ultimately had to get them clean and bright again..

@Mopar1973Man back of alternator to negative on passenger side battery, Snap On auto ranging meter, set to manual if left on auto it's all over the place when min and Max ranging I get .01-.02. 

My next steps were the one listed on Timbos website check terminal connections and all other related.  I thought APPS was causing issue due to it's failure to read true W.O.T.

Thanks

12 hours ago, WiscoRedkneck said:

I thought APPS was causing issue due to it's failure to read true W.O.T.

 

 

Yes this part is a APPS issue. Typically from people attempting to adjust the voltage of the APPS sensor for lockup issues. Once you get a Timbo's there is no more voltage adjustment issue it more of an angle measurement. It's completely mechanical APPS sensor and no logic circuits for the IVS switches.

 

 

Here are the stock APPS... Here is all the logic circuit for the IVSwhich requires proper voltage setup for it to work correctly. 

 

 

Lock up issues typically stem from AC noise issues, bad ground on the passenger battery, bad speed sensor in the tail shaft...

Edited September 27, 20177 yr by Mopar1973Man

When you have corrosion and cracked insulation on the ends of battery cables at what point do you replace them?  I'm also assuming I'll have to make my own new cables is that correct? 

@Mopar1973Man the transmission shop that installed the transmission in this truck told me if the APPS wasn't working right that could be causing hunting that's why I started there, sorry.

I'll be looking into the cables and my alternator is going to get more of a through diagnosis my old man is going to put it on one of his oscilloscope's and measure true noise on Saturday.

I have a speed sensor in my differential that indicates vehicle speed and rear A.B.S do I also have one in the transmission?

Thanks

The speed sensor in the tail shaft of the transmission is for the PCM and shift control. The speed sensor in the rear diff is used for speedometer, grid heaters, PCM for shift control as well. I've got a feeling the one in the tail shaft is your problem. Being your not saying anything about speedometer issues.

Okay I'll look into the tail shaft speed sensor.

What would you recommend for testing battery cables just ohm test them or?  Do you know what I should be seeing for resistance?