Good afternoon,
I've browsed this forum for the last several days dedicating hours to trying to find a similar problem with a solution. My truck is a 2001 Cummins with a new injection pump & FASS 150 (after throwing codes suggesting repair/replace). The problem is I will start the truck and it idles/starts fine. I can go about .25 mile and then I have little throttle response. This will usually go one for about .5-1.5 miles and clear up and then is USUALLY fine. While doing this I have also lost my speedometer also. I have pulled the TPS (after pulling codes indicating low voltage) and checked voltage off of it at pin 3. At idle I see 0.1VDC and @ WOT 4.8VDC without seeing any dead spots. I was able to mimic during this same loss of power experienced while driving, I was reading 4.8VDC without motor revving. Unfortunately before reading all the posts related to this matter I did pull the TPS off the 'throttle plate' so I could use some instructions on how to recalibrate it to that also. I appreciate all your help in this, it has been a truly frustrating venture. Thank you!

Steve

 

D'Oh!

Ok... Let's get you back up on the plat properly.
Mopar1973Man's Dodge Cummins Articles - APPS Sensor Voltage Adjustment

As for the P0122 error code you might want to read this on proper diagnostics.
Mopar1973Man's Dodge Cummins Articles - P0122 APPS Sensor Signal Voltage Too Low

As for replacement you want to order a Timbo's APPS and install it.
Timbo APPS

As for installing Timbo's APPS.
Mopar1973Man's Dodge Cummins Articles - Timbo's APPS Installing

In either case you need to retrain the ECM the new limits of either APPS sensor after messing with them... As done here...
Mopar1973Man's Dodge Cummins Articles - How to Reset / Calibrate APPS Sensor

 

Thanks for the quick response MoparMan! Was hoping that you would chime in after reading several of your wite ups. Unfortunately missing the one about the torx bit and then lucky enough to experience first hand how easily they will strip out. Quick question, will I receive a code saying no voltage detected from apps verse the low voltage?? Hopefully I can work on the truck tomorrow but a problem I may have is my fluke meter only reads x.x verse x.xx, you suggested setting a apps at 0.48 that the tag read 0.519. I couldnt tell you right now exactly what my tag states but given your scenario would setting it at 0.4 and disregarding the exact setting of 0.48 be close enough? Appreciate your help and does seem its the apps after realing effects of high idle mine being almost 1k. Again, thank you for your assistance on this!


Steve

 

This may sound like a irrelevant answer but my dad recently overfilled my trans and it caused the pedal to be real touchy and also to get the dead pedal. I emptied it out and refilled properly and it does not doo it anymore.

Also if you have a fuel pressure gauge hooked up could you tell us the fuel pressure? Sometimes the fuel filter could be clogged causing problems.

 

Hmmm...

Here is the only APPS codes there is.

Mopar1973Man's Dodge Cummins Articles - P0121 APPS Sensor Volts Do Not Agree Idle Validation Signal

Mopar1973Man's Dodge Cummins Articles - P0122 APPS Sensor Signal Voltage Too Low

Mopar1973Man's Dodge Cummins Articles - P0123 APPS Sensor Signal Voltage Too High

Mopar1973Man's Dodge Cummins Articles - P1286 APPS Sensor Supply Voltage Too High

Mopar1973Man's Dodge Cummins Articles - P1295 APPS Sensor Supply Voltage Too Low

Mopar1973Man's Dodge Cummins Articles - P0222 Idle Validation Both Low

Mopar1973Man's Dodge Cummins Articles - P0223 Idle Validation Both High

Between 0.3 to 0.4 volts should be fine. Don't want to be over 0.5 at all. This where the idle validation which will flip flop and now be stuck on throttling mode. Then you end up with a slightly high idle. (900 or so).

 

Can you post the P codes from the ecm? Also you may wan to clear the codes and relearn the apps voltages before you start chasing codes. I have seen many people chase codes that were caused by there own diagnosis and testing of a component.

Also is this only happening when the speedo fails? That is not typical of a failed apps.

 

My truck has been down since injection pump & lift pump install. I was having the same problem before swap but with not being able to idle or start without help, these two problems have been fixed by new pumps. I thought the same thing about the fuel filters so I changed them even though they had at most 50 miles on them. Trans fluid I did need to replace one of the lines so I added the fluid lost while swapping lines and does shift fine except when loss of power happens it seems to ride gears with no power to almost 2k rpms. After reading MoparMans article on resetting APPS I did pull cables and try relearning procedure without any luck. After this I did receive three codes with just having the key trick at my disposal while losing the codes for the pumps. One being the companion code, other being low voltage from TPS and the third I can get from my notepad this evening. Last night while tinkering a bit on my truck I noticed my fuel gauge was intermitting, could all these problems relate to one another or just a coincidence? The torx screws I ended up stripping one out so before trying to reinstall TPS does anyone know is NAPA has them? Thanks for the help everyone, with this much support hopefully my truck will be on the road again soon!


Steve

 

What method are you using to pull codes? Do you have a code reader or a scan tool?
When the speedo fails, does the ABS / brake light come on the dash board? I have seen some odd things caused by faulty speed sensors especially on automatic equipped trucks.

This was not a diesel but I had a speed sensor on a truck dropping to 0 and causing the trans to downshift to 1st while going down the road and I had another that the speedo would drop to 0 then jump to 160 mph and the throttle response would drip because the ecm was trying to govern speed.

It could be possible that you are chasing multiple problems. Also you mentioned that your fuel gauge was intermitting? Was that fuel pressure or fuel level? Were you moving or wiggling wires when this happened. You may have a broken or shorted wire in the loom somewhere.

Start with getting the P codes posted from the ECM,PCM and ABS. (curious about the dropping out speedo)

 

Hey everyone have an update.
Codes from PCM:
-0463 Fuel Level Sensor A Circuit High Input
-1693 Problem On The Network (companion)
Codes from ECM:
-0122 APPS Sensor Signal Voltage Too Low
-0123 APPS Sensor Signal Voltage Too High
-0216 Injection Timing Control Circuit Malfunction

On the 0216, the injection pump & lift pump are both brand new.
I also was getting the APPS codes from the PCM before, now there not appearing?

Here's where the fun begins!
I got the stock TPS back and installed, of course after reconnecting batteries the next day alarm was going off! Here are my findings. My tag reads 0.525 so I ended up setting it at 0.50. My initial test drive was same results (horrible) but after a short stop I got back in the truck and it ran like it was brand new.
I disconnected batteries again and redid the APPS calibration procedure. Truck ran awful again so decided to check voltage on TPS again without removing anything from the truck. It was reading 0.52 while idling so I adjusted back down to .50 and still gained 0.05 bringing it well over the recommended tag setting over 20 mins of idling and flicking to WOT. Something odd I also found if you barely pressed I would occasionally get a -0.02 drop right off of idle. Finally when slowly pressing the motor wouldn't start to rise till 0.64.
Its seems to me to be a faulty TPS, time for timbo?! Also, after doing some research a lot of people in other posts had a similar problem and where recommended to search for grounds but they never did a follow up saying if they where successful or not, if weather permits should I check them tomorrow? If so, is there any main ones that are known to go bad on these trucks?
I truly do appreciate all your guys help, ready to get onto the fun parts of building a diesel up and not these gremlins. Starting to think I should have kept my 12 valve!

Steve

 

All I can say is never adjust the voltage on a stock APPS...

Here is how to properly correct it.
Mopar1973Man's Dodge Cummins Articles - APPS Sensor Voltage Adjustment