Engine/Transmission (1998.5 - 2002) Autopsy of an APPS

[Sticks]

Given the number of discussions about warranty and fraud that have come up lately, rather than delete the comment, I thought I might clarify my previous statement a little.

Next week I pull the Edge out and the boost elbow to take her to the dealer right after work, now that I know that it will be right in the peak of the surging cycle.

I am doing this because;



1. My preferred service manager has transferred, and I need to feel out the new guy to see if he is one that sees a performance mod, and notes it in the file right away, thus voiding the warranty.



2. They (the dealers) have a habit of blaming the performance mod as the cause of the problem without further testing, noting it in the file and voiding the warranty.



3. I have already removed the Edge unit and driven for a week and the problem did not change, just lessened in the intensity (less HP to surge). I always do my own trouble shooting to isolate a problem before I take something to a service center to be repaired. I don't tell them what is broke, but I make damn sure that they check what I think is wrong first. Cuts down on the time they have it.



I will not knowingly defraud the dealer on a warranty issue that something that I have done caused the failure. If the part in question was damaged/failing before the mod, or there is a 95% or better chance that another component failure caused the failure of something that the MOD is attached to or controls (dead LP killed the VP and I happen to have an Edge EZ), then yeah, I expect the warranty to cover it.



The APPS is not be affected by the presence of an Edge EZ, my conscious is clear.

 

[Gary - K7GLD]

SURE hope TD didn't try to send the APPS stuff by UPS to my PO address - they might have an airhead counter person who would TAKE it, but no way for UPS to deliver to a PO...



Just patiently waiting...

 

[Texas Diesel]

Would you believe the box is sitting in the front seat of my truck?

Tomorrow is the plan.

 

[Sticks]

Originally posted by Gary - KJ6Q

SURE hope TD didn't try to send the APPS stuff by UPS to my PO address - they might have an airhead counter person who would TAKE it, but no way for UPS to deliver to a PO...



Just patiently waiting...

That was subtle.

 

[Gary - K7GLD]

WELL, for additional info, Postal stuff CANNOT be sent to my physical street address either - no mailbox there! We hafta use a PO box in town for mail delivery due to high rate of vandalism to country mailboxes, damage, theft and such - creates all sorts of problems when we order stuff - often the telephone order taker sez they will ship UPS, so we give them our street (road) address, and then their shipping department decides to send it by mail instead - to a place where there is no mailbox...

 

[Gary - K7GLD]

Got the APPS stuff yesterday - OUTSTANDING!



Looks real interesting, can't wait to strart digging in to one - but have company over the next few days - so it'll have to wait for a bit - but can see definite possibilities on disassembly - more next week...



This project is still very much alive, and WILL continue!

 

[Sticks]

Monday when I got back from my trip to Boise (I flew) I had to go run a couple of errands. As usual, there went the surging. When I got home, I ran inside to grab the wifes laptop that I brought back with me to hook up to the truck with my OBD II program so I could get some definite data on the surging.



Once again the Fickle b!tch started behaving. So I said, "Fine, we'll do it your way then. " The whole week I have hooked up the laptop before I start her up going and coming from work. NADA, ZILCH, ZERO, NADINSKY... Not one incident of surging.



Now either my particular symptoms of surging have something to do with the ECM/PCM where hooking up the laptop to it takes it out of the equation, or my truck does have a rather mean and sadistic temperament, and enjoys messing with me.

 

[FIXINRAMS]

thats what mine does,I have a snap on gr aphing scanner. no hiding from it,when even a moment glitch hits it will grab it and beep. The darn vp44 pump is so unpredictable tahe a change in outside temp can cause it to surge and even feel like she got turned off. Now that its warming up a new batch of problems get presented to deisel owners. Good luck i hope its not the vp44 but thats how it starts. Especially if you had lift pump problems or gelled up this winter Pete Gould

 

[FIXINRAMS]

Originally posted by Gary - KJ6Q

Got the APPS stuff yesterday - OUTSTANDING!



Looks real interesting, can't wait to strart digging in to one - but have company over the next few days - so it'll have to wait for a bit - but can see definite possibilities on disassembly - more next week...



This project is still very much alive, and WILL continue!

 

[FIXINRAMS]

Did anyone tell you how to calibrate the apps befor you start the motor. It must be done with a new one. Be sure the neg cables are off befor the job starts,after the installation,with the ignition on,engine not running,depress the accelerator slowly all the way to the floor and slowly release it. turn the key back off,now your new apps is calibrated to you ecm and pcm. hope you had fun and it solved your problems. What year is your ram,and don't throw the apps away,I might want to try to fix it. Pete... -- email address removed --

 

[Gary - K7GLD]

Sticks and I have been working on getting a few discarded APPS units to disassemble in an effort to study the feasibility of repairing them to return them to service - if successful, will be looking for a "victim" willing to try it out - my own truck has no surging or APPS problems - and if it ain't broke, *I'm* not gonna "fix" it!

 

[Sticks]

Originally posted by FIXINRAMS

thats what mine does,I have a snap on gr aphing scanner. no hiding from it,when even a moment glitch hits it will grab it and beep. The darn vp44 pump is so unpredictable tahe a change in outside temp can cause it to surge and even feel like she got turned off. Now that its warming up a new batch of problems get presented to deisel owners. Good luck i hope its not the vp44 but thats how it starts. Especially if you had lift pump problems or gelled up this winter Pete Gould

I am on a new VP44 as of Septemberish of 03. The surging started sometime in late November. No codes set, and seemingly unpredictable. Edge EZ on or off, no difference.



Gary - I wish you would stop gloating about not having this problem.

 

[Gary - K7GLD]

OK. here's the deal - my company has departed, I have a good number of defective APPS "carcasses" on my desktop, and will be starting on thoroughly dissecting and inspecting the first of them, perhaps today. Here is my goal:



Determine a satisfactory way to disassemble, troubleshoot and repair them so a reasonably competent owner can duplicate the above, then reassemble it and put it back into service



I have perhaps better than average test equipment, maybe a bit better than average electronic/mechanical skill level - but certainly am NOT a "guru" or electronic/mechanical genius. I really want to establish a test method to apply power and signals in/out of the APPS to monitor its operation in a reasonable fashion. I have power supplies, test meters and a very good oscilliscope. Hoping these will be enough, I intend to try to actually SEE what is going on inside the failed APPS units, and then, after hopefully fixing the problem, establish it is operating properly before attempting to return it to service - if I get that far!



It has been established that knowledgeable individuals from DC read these threads - if ANY of them, or other similar individuals have ANY helpful info or test procedures to offer, feel free to pass them along here, or directly to me via Email - confidentiality will be observed, if requested.

 

[Gary - K7GLD]

Using the wiring info posted elsewhere in this thread, we have these connections in/out of the APPS:



the connections to the ECM from the APPS:





APPS ECM

---- ---

1 >--------BK/LB--------< 11 (B+)

2 >--------LG/DB--------< 16 (Idle Val. Switch 2)

6 >--------BR/OR--------< 1 (Idle Val. Switch 1)

4 >--------BK/YL--------< 32 (APPS Sensor Ground)

3 >--------LB/BK--------< 25 (APPS Sensor Signal)

5 >--------DB/WT--------< 31 (APPS Sensor Supply)





I'm assuming 12 volts will work into #1, and ground, -12 volts to #4... Then, is #3 where I would expect to see APPS output, or would a connection between #5, the "sensor supply" and #3, "sensor signal" be the monitoring path - or what other external connections/signals must be applied to obtain a useful output signal from the APPS to look at. Anyone know?



Approximate expected values would be nice to have as well...

 

[15w40]

Gary - KJ6Q, I would use an oscilloscope to measure the APPS. You don’t have to worry about connections to 1, 2 and 6. These are the idle validation switch and it never fails.



The ECM supplies 5 volts to connection 3 and ground to connection 4. Think of these connections as the two end points of a potentiometer with connection 5 as the wiper. If you supply a 5-volt source to 3 and ground to 4 and also ground your scope to 4, connect the scope input to 5. A good APPS will show a steady falling or rising trace as the APPS is moved. The chances are, you will see the line move at a steady rate where the APPS is not worn, and violent shifts where it is worn. If you can clean the APPS to restore the smooth response, this is the info everyone will want to know.



I made an edit to the terminal numbers for this newer sensor. It looks like they swapped terminals 3 and 5 from the older sensors. It should be possible to use the scope to check for a smooth response from the sensor. All the electronic junk in this newer sensor is only to replace the micro switch. I still need to finish the schematic to get more answers.



There is only one large resistive area that the ECM uses to find the throttle position. the smaller area next to the larger area is only used to make the wiper contact. The second set of small and large resistive areas are used to feed the circuit that replaces the micro switch. What was DC thinking when they came up with this design?

 

[Sticks]

Gary - Looks like you are off to a good start. Mine are burried on the workbench under sawdust, paint brushes and other general wood working crap. I did start to at least get ome resistance readings off the 4 that I have. I had planned on running out to Cummins to see if I can get a plug that would plug into the APPS so I would not have to fight with holding to leads against the pins and still turn the spindle. Maybe Thursday, since tomorow I am helping someone install some shocks on thier truck.



As soon as I get the resistance values on them, I will post them, along with the voltage readings off the tag (all four are dfferent).

 

[Gary - K7GLD]

Dave - thank a bunch!



Saves LOTS of time avoiding duplicating effort and running down deadend paths when we get this sort of helpful info!

 

[Sticks]

Dave must have posted the same time as I. I have no oscilloscope. I presume that a digital voltmeter is not going to be sensitive enough for this?

 

[Gary - K7GLD]

Sticks, a digital VM is not capable of displaying rapid small variations in voltage swings - an analog meter is better, but still not really good enough - but at least an analog MIGHT let you see there ARE voltage variations. A scope will let you actually SEE the swings, regardless how short their duration, or how little they swing.



By the way, you mentioned wanting to get a plug for the APPS for connecting power and monitoring operation - all you really need are some clip leads - Radio Shack sells several kinds that will work nicely, and can be used for other purposes as well.

 

[Gary - K7GLD]

Rather than append this thread with what would be better served in a new one, I have started this one:



https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=99611



Spent time with one of the APPS units today, and after disassembly and a reality check, what's in the above thread seems the best overall approach for the broadest spectrum of owners...