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

[mhenon]

... I tend to think that the DC settings follow the universal set of standards, or at least the ECM will accept the universal set of standards settings... .

I haven't done near the testing you're doing but that's what I came up with on one OEM APPS and two Williams APPS. Karls take on the spec's were just what i was seeing on my meter.

Mike

 

[rweis]

AND,



We are ALL on the same page for a change (which IS THE MOST IMPORTANT PART of this whole APPS testing modification concept). A MAJOR MAJOR contribution by KarlC.



I built the bracket, installed the micro switch, set it to the standard, DONE (had a few false starts and wiring deviations along the way ).



Guys just changing the APPS, install the APPS, set it to the (same) standard, DONE.



NOT guessing "what did DC do here?"



Bob Weis

 

[Gary - K7GLD]

We have been quite fortunate in finding the Williams Controls site, and the widely varying options they offer as potential substitutes for what DC used in the APPS. We as a group, have been even MORE fortunate that Timbo has developed, and is distributing a direct replacement APPS, built around one of the Williams APPS modules, which so far seems quite successful - let's hope that approach continues to rack up MANY successful miles!



BUT, let's NOT put all our eggs in one basket - and prematurely stop continued efforts to find additional options, or further refine what we have already established - with the goal of rendering them more easily copied and used by owners with limited abilities and tools.



In my own case, use of a potentiometer TOTALLY foreign to this type service, and the MS for the IVS, went smoothly and trouble-free, in spite of complete lack of attention or measurement of related voltages - checking resistance and matching to the OEM APPS seemed to be close enough for it all to work properly - truth is, there's really not much room for error is setting the MS operation - too close and it bottoms out, too far away, and it won't trip!



BUT, perhaps my own setup success was pure luck - and to continue my own route of testing, I plan 2 more similar setups - one using the pot section only of a "failed" APPS and added MS for the IVS function - and the other, will be one of the Williams modules, but the potentiometer-only version, to which will also be added the MS for IVS function.



I personally feel that AS LONG AS we use a potentiometer total end-to-end resistance spread in the 2500 ohm or so range the ECM wants to see, and reasonably center actual potentiometer wiper in the middle of that range (my OEM APPS measured a swing of about 1600 ohms, with 300 unused on the low side, the rest on the WOT side), there is no NEED to be overly concerned about voltages - and the MS needs only to be adjusted to trip just a bit off idle, and then return reliably back at idle - which is no real trick, since mechanically, that's the ONLY way it installs anyway!



I may well be all wet in my theory - but I'll find out soon enough! :-laf:-laf



I've pointed it out before, and will again - I have poor faith in the use of typical electronics switching for the IVS, and while the Williams setup MAY be more robust in design and reliability than the OEM one DC used, we don't KNOW that for sure, and I hate to abandon other potential substitutes, only to find out later that the Williams setup presents all the SAME failure tendencies the OEM one does, and for all the SAME reasons!



And yes, the external, MS approach is ALSO very much untested, and MIGHT prove to have serious shortcomings and issues of it's own - so we need as much testing of ALL options as possible - the MORE potential solutions we have under test, the better.

 

[rweis]

Gary-



I think I can write up exactely how to weld together the 3 piece bracket I did. I am also thinking of taking it to a fabricator and getting 5 - 10 fabricated (have to get an estimate to see where the $$$ will be) so it is a bolt on bracket, bolt on micro switch, set the micro switch to Karl's standards and DONE.



Sort of the same concept of Mike doing the pig tail, except it would be a different pigtail that would go to the microswitch and APPS pot, and the micro switch bracket.



Bob Weis

 

[Gary - K7GLD]

I just got off the phone from ordering one of the Williams APPS modules - ended up with their 131032 version, on their recommendation, altho' they also show a 132144 that LOOKS like it should work the same, but is cheaper, and has no attached IVS - which I don't plan to use anyway. :{



One side benefit to the IVS version, is the possibility to inspect it to see if any glimmer of insight as to construction is visible to compare against the DC version...



This DOES tend to get a bit expensive, the version I ordered was $97 plus shipping... Sorta painful, especially since My OEM APPS and the substitute are both working fine, and I need another one like I need another hole in my head... :-laf



OK, enough whining for today... :-laf

 

[JLandry]

I just got off the phone from ordering one of the Williams APPS modules - ended up with their 131032 version, on their recommendation

Gary,



That's the version I wound up with. I have it sitting here on my desk ready to install in my truck with a modified Williams wiring harness attached (the two original Weatherpack connectors cut off and a single Deutsch connector installed). Pictures attached. Now I'm just waiting for the chance (good weather and time) to measure the voltages on my OEM APPS (for base reference), then install and calibrate the new Williams APPS in it's place.



BTW, the actual sensor you'll get with your kit is part number is 131856, but for some reason they don't sell that sensor as a separate item (which doesn't make any sense to me), so instead you'll get the sensor and some screws to toss in a coffee can... but then you probably know all that already.



Best regards,



John L.

 

[Gary - K7GLD]

Gary,



That's the version I wound up with. I have it sitting here on my desk ready to install in my truck with a modified Williams wiring harness attached (the two original Weatherpack connectors cut off and a single Deutsch connector installed). Pictures attached. Now I'm just waiting for the chance (good weather and time) to measure the voltages on my OEM APPS (for base reference), then install and calibrate the new Williams APPS in it's place.



BTW, the actual sensor you'll get with your kit is part number is 131856, but for some reason they don't sell that sensor as a separate item (which doesn't make any sense to me), so instead you'll get the sensor and some screws to toss in a coffee can... but then you probably know all that already.



Best regards,



John L.

Thanks for the info and pics John - the Williams website is greatly lacking in specific info on their modules - other than physical dimensions, pretty slim! And their "tech" really didn't have much info other than what's on their website either - the cheaper unit that LOOKED like only the pot section, and what I *really* wanted, had NO info or pics as to shaft type, or spec as to whether there was even slim hope offered it would mount to the DC bracket assembly and shaft - and I wasn't about to gamble on it...



I have one of the Deutsch plugs here I can use, but will have to get the Weatherpack connector for the Williams end (was that a NAPA item?). I'd LOVE to get a peek at the innards of the IVS section, as well as the interconnect from the innards to the pins, to see if it's a better setup than the DC version - but not about to butcher one up to find out...

 

[JLandry]

... the cheaper unit that LOOKED like only the pot section, and what I *really* wanted, had NO info or pics as to shaft type, or spec as to whether there was even slim hope offered it would mount to the DC bracket assembly and shaft - and I wasn't about to gamble on it...

Gary,



Let me clarify something...



When you said you ordered the "131032 version," I wasn't sure if you literally ordered that part number or the "Service Kit" for that part number.



If you indeed ordered Williams part number 131032, you will get the following items in a kit:



1 each 132144 Housing

1 each 131856 Sensor (APPS)

2 each 131308 Screw



That "Housing" above looks like a plastic or phenolic spacer of some sort used on some systems. I don't think you'll need it. The good news is you'll still get that sensor you wanted.



Now if you order Williams part number 131973 (known as a "Sensor Service Kit"), you get:



1 each 131856 Sensor (APPS)

2 each 131308 Screw



Note the "Housing" is left out.



Either way you get the sensor.



See attached.



John L.

 

[Gary - K7GLD]

When I indicated the #131032, there was no mention of a "service kit", so I'll likely end up with parts I won't use, as you suggest. Where did you buy the 6-pin connector that attaches to that Williams module, and what part # ?

 

[JLandry]

Where did you buy the 6-pin connector that attaches to that Williams module, and what part # ?

Gary,



I actually took the lazy way out and ordered a wiring harness from Williams (their part number 131165) when I ordered the APPS from them. The harness is designed to plug directly into the 131856 Sensor and has the two Weatherpack connectors on the other end. It costs $26. 41.



Although, I think someone else posted the source of the connector you need recently in this thread (good luck finding it).



John L.

 

[Gary - K7GLD]

Well, Mouser sells one that LOOKS like it is correct - and is under $2 - will wait until the Williams APPS arrives, and go from there, I have other stuff I need to order from Mouser anyway, so just as well combine the shipping $$$ - thanks.



OH, and will be leaving early in the morning for a long weekend trip down to the Lodi (Ca) area to visit daughter and family, so will miss the weekend action here most likely, unless I take my laptop PC with me - the daughter's desktop PC has died, and one of the things I'll be doing there, is trying to resurrect it... :-laf

 

[timbo]

When I indicated the #131032, there was no mention of a "service kit", so I'll likely end up with parts I won't use, as you suggest. Where did you buy the 6-pin connector that attaches to that Williams module, and what part # ?

Gary this is the connector you need Casper's]Casper's Electronics, Inc. : 6 way Metripack PTS 150. 2 Female Electronics, Inc. : for the 131032 sensor but you will get that housing that you don't need. That is the sensor i'm using, I got a couple here i don't know what to do with. The application is cummins Navistar. Saying that the part #s are confusing is an UNDERSTATEMENT, when i called my dist. looking for just the sensor he was shooting off so many part #s my head was spinning. Tomorrow I got 10 coming, I hope they are correct.

 

[Gary - K7GLD]

Gary this is the connector you need Casper's]Casper's Electronics, Inc. : 6 way Metripack PTS 150. 2 Female Electronics, Inc. : for the 131032 sensor but you will get that housing that you don't need. That is the sensor i'm using, I got a couple here i don't know what to do with. The application is cummins Navistar. Saying that the part #s are confusing is an UNDERSTATEMENT, when i called my dist. looking for just the sensor he was shooting off so many part #s my head was spinning. Tomorrow I got 10 coming, I hope they are correct.

Thanks for the pointer - I probably will need it - and GREAT on ordering additional Williams APPS units, that a good sign all this thread effort is paying off for members here!



You may get the market cornered, and retire early! :-laf:-laf

 

[timbo]

Thanks for the pointer - I probably will need it - and GREAT on ordering additional Williams APPS units, that a good sign all this thread effort is paying off for members here!



You may get the market cornered, and retire early! :-laf:-laf

Actually the 10 that HOPEFULLY get here TOMORROW, are already requested. I just hope they are right so i know the correct part# and it is actually VERIFIED to be the correct sensor kit so i can order more. The entire part# battle has been long, I've spent a considerable amount of time on the phone so far. Tomorrow i hope it will finally be straightened out.

 

[JLandry]

Confused!

OK guys,



I just went out and took voltage measurements of the original DC APPS on my truck... it's never been touched. My truck has an auto transmission and over 90,000 miles on it.



Some of the measurements were interesting and some confusing to me.



The APPS calibration sticker says: . 618 VDC



Using a digital multimeter, I measured the following voltages at the Deutsch connector which plugs into the DC APPS...



DB/WT wire, pin 5 (sensor supply)

4. 96 VDC​

LB/BK wire, pin 3 in connector (sensor signal)

Idle - . 522 VDC (actually, this measurement varies from . 513 to . 530 when I wiggle the accelerator bell crank)



WOT - 3. 64 VDC



That makes the voltage span 3. 118 VDC​

LG/DB wire, pin 2 (IVS ?) Voltage is present on this pin with bellcrank in the accelerator OPEN position.

. 878 VDC on sensor (pin 3) when opening, . 803 VDC on sensor when closing​

BR/OR wire, pin 6 (IVS ?) Voltage is present on this pin with bellcrank in the accelerator CLOSED position.

. 845 VDC on sensor (pin 3) when opening, . 785 VDC on sensor (pin 3) when closing​

BL/LB wire, pin 1 (IVS ground)

No voltage present at any time no matter what the bellcrank position. I verified this pin has continuity to ground at all times.​

OK, so now some questions...



1. What is the voltage listed on the sticker affixed to the DC APPS supposed to match? As you can see from my measurements it doesn't seem to match anything.



2. When voltage is measured on pin 2 or 6 which connected to the IVS, does this tell me the switch is open or closed?



I'm not going to install the Williams APPS until I understand the IVS circuit a little better and can verify I have the new wiring harness for the Williams APPS wired correctly. I need to ponder this.



Thanks in advance,



John L.

 

[rweis]

OK guys,



The APPS calibration sticker says: . 618 VDC



DB/WT wire, pin 5 (sensor supply)

4. 96 VDC​

LB/BK wire, pin 3 in connector (sensor signal)

Idle - . 522 VDC (actually, this measurement varies from . 513 to . 530 when I wiggle the accelerator bell crank)



WOT - 3. 64 VDC



That makes the voltage span 3. 118 VDC​

LG/DB wire, pin 2 (IVS ?) Voltage is present on this pin with bellcrank in the closed position.

. 878 VDC on sensor (pin 3) when opening, . 803 VDC on sensor when closing​

BR/OR wire, pin 6 (IVS ?) Voltage is present on this pin with bellcrank in closed position.

. 845 VDC on sensor (pin 3) when opening, . 785 VDC on sensor (pin 3) when closing​

BL/LB wire, pin 1 (IVS ground)

No voltage present at any time no matter what the bellcrank position. I verified this pin has continuity to ground at all times.​

I would make a spreadsheet with the supply voltage (direct read), the idle range 10% - 20% (calculated), the WOT range 70% - 85% (calculated), the span (calculated), the IVS range 3% - 10% (calculated), I added what the actual voltage that the ECM allows the throttle to be passed to the VP44 (ie acceleration), then make another column of actual.



My idle set point range is . 5 - 1. 0 my actual is . 527,

my WOT range is 3. 50 - 4. 25 my actual is 3. 62,

my span is 3. 0 - 3. 25 my actual is 3. 093,

my IVS is . 620 - . 836 with 6. 5% @ . 728 my actual is . 702,

ECM allows throttle up at . 715.



All taken with key ON, engine OFF. Engine ON idle is . 580, throttle up . 717.



I took ALL my measurements and made ALL my adjustments except the supply voltage based on pin 23 C3 (PCM). I think you may get some different values because the ECM is also part of the voltage measurement.



Well, first the sticker on the dc APPS is supposed to equal pin 23 on C# over on the PCM. Ideally they are the same. However it is so sensitive that it is hard to get them really close.



The supply voltage is just that = 4. 96



I am using a micro switch for the IVS so the IVS voltages will not be meaningful.



Welcome to the REAL fun of trying to make logical sense of it all in a cohesive picture.



Bob Weis

 

[KarlC]

LG/DB wire, pin 2 (IVS ?) Voltage is present on this pin with bellcrank in the closed position.



BR/OR wire, pin 6 (IVS ?) Voltage is present on this pin with bellcrank in closed position.

Voltage is present on both pin 2 and 6 when the bellcrank is in the closed position. Is this right?

BL/LB wire, pin 1 (IVS ground)

No voltage present at any time no matter what the bellcrank position. I verified this pin has continuity to ground at all times.​

OK, so now some questions...



1. What is the voltage listed on the sticker affixed to the DC APPS supposed to match? As you can see from my measurements it doesn't seem to match anything.

I would say the voltage coming from the APPS IS supposed to match the sticker at idle. The APPS may have changed over time.

2. When voltage is measured on pin 2 or 6 which connected to the IVS, does this tell me the switch is open or closed?

Since the switch is pulling to ground (0V), when you see voltage the switch should be open.



Karl

 

[mhenon]

... The APPS calibration sticker says: . 618 VDC



What is the voltage listed on the sticker affixed to the DC APPS supposed to match? As you can see from my measurements it doesn't seem to match anything... .

John, The voltage on the sticker should match the reading you take at pin #23 on the PCM. I assume this is the same as pin #3 (signal or wiper) on the OEM APPS but won't say that for sure. Just go to pin #23 on the PCM and check your idle voltage. If it doesn't match what you see on the calibration sticker. . then loosen the two screws on the APPS and move it to get as close as possible. Yes. . the voltage will change somewhat every time you move the bellcrank. Mine was all over the place each time I did that but try to get close. Good luck.

Mike

 

[JLandry]

Still Confused

Voltage is present on both pin 2 and 6 when the bellcrank is in the closed position. Is this right?

Karl,



That was a typo on my part. I went back and corrected my post. Sorry for the confusion... it just goes to show that double and triple checking my post before hitting submit still wasn't enough.



It should have read:



LG/DB wire, pin 2 (IVS ?) Voltage is present on this pin with bellcrank in the accelerator OPEN position.

. 878 VDC on sensor (pin 3) when opening, . 803 VDC on sensor when closing​

BR/OR wire, pin 6 (IVS ?) Voltage is present on this pin with bellcrank in the accelerator CLOSED position.

. 845 VDC on sensor (pin 3) when opening, . 785 VDC on sensor (pin 3) when closing​

Since the switch is pulling to ground (0V), when you see voltage the switch should be open.

That's what I thought, and that's what makes me confused. The idle validation switch logic on my OEM APPS seems backwards.



It seems everyone agrees that pin 6 on the Dodge wiring harness Deutsch connector is for idle and pin 2 is for throttle. Referencing the corrected APPS/IVS wiring diagrams posted earlier in this thread, it suggests that the idle validation switch connected to pin 6 should be *closed* when the APPS is in the idle position. Since I'm measuring voltage on that pin when my OEM APPS is at idle, it means the switch is in fact open... just the opposite of what I expected it to be!



Likewise, I thought pin 2 for throttle should be open at idle and closed when the APPS is not at idle. Since I measure voltage on that pin when the bellcrank is open, it also means the switch is open when the bellcrank is open... completely backwards from what I thought.



So what's going on here? The idle validation switches are OPEN during the tested state?



Maybe I should cross check my voltage measurements one more time to be sure I didn't write things down incorrectly, but I swear I checked them several times each already because I couldn't believe what I was seeing.



Best regards,



John L.

 

[JLandry]

Just go to pin #23 on the PCM and check your idle voltage.

Thanks Mike,



I'll do that.



John L.