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

[timbo]

AWESOME job Mike, now thats plug and play!!!!!!

 

[Gary - K7GLD]

So, Mike - that is the $100 APPS - and has internal mechanical contacts and NO electronics?

 

[mhenon]

So, Mike - that is the $100 APPS - and has internal mechanical contacts and NO electronics?

I'll have to check price but mine was a few more bucks than the one Bob picked up. . something like $120. 00. I ordered it over the phone from Portland, Or. . I'll get more info and post it.

As far as the internals my guess would be it's just like our OEM APPS with some small circuit board and wiper fingers sctratching across a mylar sheet. One would hope they built it a little better for the transportation industry but I wouldn't bet the farm on that.

Mike

 

[rweis]

Say what?



Just to be sure I understand:



Wilson



APPS



A White to dc 4 black yellow ground

B Black to dc 3 light blue black signal

C Red to dc 5 dark blue white 5 volt



IVS



A Orange to dc 1 black light blue ground

B Blue to dc 6 brown orange idle

C Green to dc 2 light green dark blue throttle



"The idle voltage at pin 23 was a little high (. 724v vs . 525v with the DC APPS) when the bus APPS was in place on the bellcrank. Just back off the the idle set screw and get it as low as you can. This turned out to be . 634 volts. I then cranked in on the set screw until the idle voltage came up a hair. . like . 635v. Didn't want the stop point to be the internal stop on the APPS. Same thing on the upper stop screw. WOT on the DC APPS was 3. 336 volts and 3. 836v on the bus APPS. I forgot to write down where I set that but it doesn't matter. . the ECM will learn it. "



With everything buckled up I did the key on pedal to the floor reset and took off for a test run. (Disconnected the batteries for 30 minutes?)



I'll try that in the am, I'll be d... ed



Thanks, thanks a WHOLE LOT,



Pm me your phone number where I can reach you mid am tommorrow in case mine acts differently than yours.



Bob Weis

 

[KarlC]

Great job, Mike. This may be the best alternative for someone who wants a truly quality setup with not much effort. Oo. Oo.



Sometimes I think about whoever buys my truck when I'm ready to sell it, and what I'd tell them about mods I've made. A retrofit like this would be easy to explain and not put people off.

 

[mhenon]

Thanks guys! Just pm'ed Bob and explained I was getting ready to rig up the relays and fired the engine on a whim. Voltages looked close so I figured an MIL would be worst case. SURPRISE!

Really need to put a few miles on it before getting too happy but at this point I'm confident it will work for us.

Mike

 

[rweis]

OK, let's assume that it works as advertised, and I think it will.



Now we need a source for the sensor & wire harness.



I got mine at ABC bus company as a VanHool service Bulletin No. 1103. Coach Model T 2100 and C 2000 Series. The P/N is VH 10693907.



In that service bulletin the P/N of the Accelerator pedal complete has changed and was VH 10588255 and was changed to VH 10970306. The complete assembly was $623. 15 + 7% tax at ABC bus. IF anyone is going this route. This complete assembly is a lot cheaper on the Williams Controls - Elec. Throttle Contols and Valves site.



Williams Controls makes them.



If someone would verify the order would be:



"WM526 model, part number 351314 Cummins, DDEC III & IV, w/IVS, Mercedes North America, Service Kit, Sensor kit 132034 which includes the screws, wire harness, sensor, and wire clamp or the sensor only has the integral wire harness and is P/N 131856"



EXACTELY which one? I would think P/N 131856 since it has the integral harness and we already have the screws from the dc APPS you are taking out. (Further research indicates you can not buy just the sensor, you also have to buy the 2 screws. The P/N for the sensor and 2 screws is 131973. However the picture on the Williams Control page for 131973 (131973 Parts Kit for Cummins and Mercedes North American Engines) does NOT show the wire harness which you will need at least 1 of)



Mike got his from a different source than ABC bus. I got mine from ABC bus and it was $100. 96 + 7% tax. Mine included the wire harness.



At ABC bus I had to have an account to purchase for their accounting department. Just name and address and only took 5 minutes to set up, but had to have an account none the less.



A Williams Controls internet store front seems to be 131973 Parts Kit for Cummins and Mercedes North American Engines

which is exactely the sensor 131856 and 2 screws (see comments about the wire harness). It states the sensor is not sold seperately. $94. 54 ships usually next day, 1 in stock, $10. 45 shipping to my zip code, total $104. 99. This site seems to be connected to Williams Controls, and seems to be able to sell 1 at a time, best price it seems. I went through the purchase system and it will indeed let you buy 1 at a time either set up an account or buy anonymously.



The P/N 131973 seems to be the number we want from Williams Controls which is the sensor and the 2 screws. BUT as mentioned above I am not sure if it includes the wire harness to get from the sensor to the dc ECM harness. We need to check that point. The nominclature on the Williams main site implies the wire harness is integral to the sensor.



Wire Harness P/N 131165 if you need that. P/N 131973 does not come with a harness which you only need to buy 1 time. P/N 132034 Service Kit comes with sensor, screws, harness which is probably the way to go the first time you get this sensor because it has the harness in the kit.



Bob Weis

 

[ScottLauer]

I just wanted to get on here and say THANKS A LOT! Now that you guys are so close to finding a good answer to this problem I wanted to express my gratitude for your time,effort and resources that you guys have used to accomplish this. I (and I'm sure MANY others) are anxiously waiting the outcome of this. I personally look at all the electronics gizmos and gadgets and go Like it's been said many many times before this place is the best money I've ever spent.



THANKS A MILLION GUYS!

 

[mhenon]

Bob, Here's some info on Williams Controls the company that makes the pedal assembly and APPS sensors. I had called them to order my pedal and sensor but they wanted to start an account so they suggested I call a bus company, like you did, and order there. Here's the Williams bochure:

http://www.wmco.com/products/throttle_controls_catalog.pdf

The pedal I bought is the WM526 w/sensor kit. The sensor kit is the actual 6 pin APPS with about 2' of pigtail terminating in 2 Weather Pack connectors. This sensor (or APPS) came already attached to the pedal assembly. I also bought a spare sensor (APPS with 2' pigtail just like the pedal). I'll give some ordering info here for anyone interseted. I would imagine any trucking repair shop could order this for you. If someone here wants to go to the trouble of starting an account directly with Williams Controls you could give all TDR members a discount and still make yourself a few bucks ( i'm still amazed one of the aftermarket boys didn't research this YEARS ago).



1. Williams WM526 Electronic Accelerator Pedal. . I paid $265 plus shipping

part # 350825, 350826 & 350827

The only difference in these three pedals is the tilt of the toeboard (see page 7 on above web-site). Remember this pedal was designed for the commercial truck/bus industry so they provided several options as to fit. I ordered the WM526 pn# 350826. I set it right next to my stock pedal and it looks like the tilt of the pedal is just about right. I figured I could change this somewhat if needed by shimming the toe or heel of the pedal.

2. Sensor Kit - Cummins/Mercedes north America. . I paid $ 127 plus shipping

part # 132034

This is simply the APPS with 2' of pigtail terminating in Weather Pack connectors. If you just want to replace your OEM APPS this is what you need. I'm sure this is what most folk would want to do. Like Bob said earlier it bolts right to the DC bellcrank. You will need to fabricate a jumper (six wires) between the Williams connectors and the Dodge connector (Weather packs to OEM) with one of these: Deutsch DT Series 6-Way Connectors . Once this little jumper is made. . the whole swap of the APPS is really plug & play. I can see where making up this jumper might cause some folts to hesitate but it's not that hard. I'll make a few up in time and try to have them available if you don't want to tackle this job.

Mike

 

[mhenon]

I should have said something about the other sensor (APPS) listed on Williams page. For those wanting to go with a mechanical switch to control IVS it looks like the DDEC I, II, II & IV - Sensor kit pn# 130303, 132035 or 131140 would work (I'll bet they would work!). Don't have any idea if they would mount right up like the WM526 sensor though. Just looking at the illustration the bolt holes look the same. Again. . one of the trucking repair shops could probably tell you if the bolt pattern matches (Bob. . maybe your bus shop could help out there!).

For me. . I'm pretty happy with the replacement sensor alone. I plan on eventually installing the whole pedal assembly in the cab (that takes care of engine heat problems) but want to road test this APPS for a few hundred miles first.

Mike

 

[rweis]

Ok, put everything back to "normal". ALL the dc wires are soldered to the WeatherPacks so the Williams just plugs right in. I also "re-terminated" my good dc APPS to match the Williams plugs so I can go between the bus APPS or the dc APPS just by switching the hardware pot and tweaking the idle stop. Gotta love it "the dc APPS is a SPARE!"



Now on the idle stop. Today's info:



The engine will crank and accelerate fine, BUT. I have done the APPS reset thing but NOT removed the batteries (what is being done right now).



I had about 1/4" of bellcrank travel before the IVS would signal the ECM to accelerate. The initial voltage on pin 23 was . 495. Acceleration did not happen until . 820. When the voltage got to . 820 it accelerated fine. I tried to adjust the idle stop to see how much travel had to be taken up by the idle stop screw - about 1/4" - which is about all the travel you CAN compensate for by adjusting the idle set screw.



I cleared the codes (0222 low IVS voltage on BOTH lines) and now only have 0121 that the ECM voltage does not agree with the APPS and hence the voltage drain down in the ECM right now.



BUT the bus APPS is a plug and play with the harness mike is talking about to get from the OEM connector to the WeatherHead connectors.



I am hoping that draining down the ECM will clear the 0121 and will eliminate the ineffective pedal travel at the idle end of travel.



I'll report back when the 30 minutes is up and batteries are reconnected.



Bob Weis

 

[rweis]

Called Mike to compare notes:



He has a manual, I have an auto. We think that the APPS voltages are a little different between the manual and the auto like the auto PCM circuits lower the APPS voltages . 1 volts.



Therefore the position of the bell crank changes betweent he two manual and auto versions.



More to come



Bob Weis

 

[Gary - K7GLD]

Well, no doubt about it, the price difference between the OEM APPS at well over $400, and the Williams at about $100 is VERY encouraging!



HOWEVER, that said, if that device still uses a similar form of electronics IVS switching and the pressure-type interconnect between the electronics section and the connecting pins, all the same issues as with the DC APPS remain.



I'm sure we will get more info on this specific approach as time passes - but hope a few of us continue with other potential alternatives as well...

 

[rweis]

I still can not get the 0222 to clear and stay cleared.



There is a relationship here that I think I do not understand. I did manage to get a 0223 IVS signal (> 5 volts) too high once. I also had 0121 the ECM voltage not matching the APPS etc. I also had a 0222 both IVS signals low.



I need some of the auto guys give this thing a try and maybe you will do something different than what I am doing.



It is getting very frustrating. There is a detail somewhere that causes the 0222. What is it? I know what the code reads, but WHAT is it really saying? Is it saying that the circuitry in the bus APPS has too much resistance and therefore the voltage going down the idle line and throttle line is too low? What is the minimum anyway and where is it measured?



Exactely how does the idle set screw come into play? Is it set so just when the APPS voltage starts to climb it is set there?



There are more interactions than are obvious. Ideas?



Why does the manual transmission work easily and the auto transmission not using the exact same procedures? What does the auto transmission add to the mix? and how?



How do you clear the APPS voltage reference out of the ECM? I tried disconnecting the batteries for 1 hour, reconnect batteries, do the APPS calibration procedure and still get the 0121 at times, not every time, but at times.



Bob Weis

 

[rweis]

Well, I stuck it out and it is running fine, with no codes, with the bus APPS, no resistors, just clean wiring. OH BTW I drilled the APPS pocket with 3@ 3/8" holes on top to help ventilate the APPS pocket with the VP44 blower. With the VP44 blower shoveing OAT into the VP44 and now with the 3@ 3/8" holes the air flow is very noticable out the top of the APPS pocket. It cin only help the APPS stay cool which is a good thing I think.



I think I know what I do not know. EXACTELY what happens and EXACTELY how do you reset the ECM APPS values and EXACTELY what is the sequence?



I do know it is not key on, slowly depress the pedal to the floor and slowly let it back up, turn off the key, and it is reset. There is something else to it - engine start? key off for some period of time? there is something else to it.



The reason I think so is because I kept getting 0222 IVS low voltage and was trying to find what would cause it. I was not getting 0121 that the ECM and APPS disagreed. I go t so frustrated I put the OEM APPS back in and did the APPS reset procedure, and started getting 0121 that the ECM and APPS values did not agree. BUT I DID THE RESET PROCEDURE? So I tried it several more times, same problem. Then suddenly I did not get the 0121 code. Why? Does it take the ECM xx amount of time to do it? Why would it suddenly clear itself?



Then I thought I would go back tothe bus APPS because there is no APPS mounting screw adjusting and that would take out one variable.



Put the bus APPS back in, did the reset, key off, started the engine, stopped the engine, got the 0121, ate dinner (time elapse), went back to it and the 0121 code was cleared.



WHY? EXACTELY what what happens and when and how when you reset the APPS with the pedal procedure? Am I missing a step?



Anyway, bus APPS in, no codes, accelerates fine. I sure would like to understand what is happening better. I totally do not understand why it is working, it is, but I do not totally understand why?



Bob Weis

 

[mhenon]

Bob, I think AutoZone and others will clear the codes for you. Don't know if/what they charge. I have a ScanGauge II and can clear my own codes. I've found though, even with ScanGauge some of the engine codes are tough to clear. On the most persistant I've had to clear the code and then disconnect the battery before restarting.

If you can clear that code I would keep bumping up that idle voltage with the setscrew until the low voltage code went away. I know thats a pain without a way to constantly clear new codes but hang in there. You might be closer than you think if not already there. Remember. . the codes hang on even when things are fixed.

Mike

 

[mhenon]

Just made a run today of 150 miles. Nothing to report as it's all working fine so far.

Bob, I just went out and checked the idle and WOT voltages:

idle (against the stop) . 636v.

WOT (against the stop) 3. 855v.

I don't know if the upper voltage means much but you might want to shot for something around . 6oo volts or better for the idle.

Mike

 

[rweis]

I clear my codes with a Smarty. I even went back to stock ECM to see if that would make a difference.



I measured . 435 when I was able to get acceleration. I need acceleration in the morning to tow my RV so left it right there. . 435 seems pretty low, but if it works then it is fine with me.



I am going to reread about the APPS. I have got to be missing something, or something I truely do not understand about how to replace one APPS reference voltage with another APPS reference voltage. Sure would be nice to be able to read what the APPS reference voltage stored in the ECM was / is.



Anyway, I have a 1693 companion code set code, but that is trivial. No other codes. No 0121, 0222, 0223. When I got the 0121 the APPS would NOT accelerate regardless. It would accelerate with the 0222 and the 0223, just had the MIL light on. The 1693 does not turn the MIL light on.



I'll see how . 435 drives. I would guess I am going to have to raise it more toward . 600 as you mentioned. It had always been at . 55+ up to about . 600 before. The IVS / ECM does not allow engine acceleration until the voltage reaches . 78 so I do have a bit of dead pedal before the bell crank gets to the acceleration voltage of . 78, then it accelerates fine.



There is more to this than meets the eye, but it works with an auto so far.



I think with proper mileage testing and in particular temperature testing (ie at least 1 year so we see how the cold effects it and the hot summer effects it) we may really have a good fix. Even if you replace it every 100k, that is not all bad.



The DEEC with out the IVS may be a better fix in the long run to get the IVS on a MS for longevity and probably simplicity (ie individually settable).



I have been running the dc APPS almost 6 years and 90k miles without problems, but I also run an OAT blower 90 minutes after shutdown. With the holes in the top of the APPS pocket you could literally take the APPS temperature if you wanted. I know just idleing it in the driveway during testing the APPS aluminum pocket frame got HOT. Aluminum is a GREAT conductor of heat, bolted right onto the HOT engine and the APPS pot / IVS curcuits then stuck in what amounts to be a closed baking oven. Makes zero functional sense to design it that way. After I shut it down and the blower was running I did an air flow check out the top of the APPS aluminum frame where I drilled the 3 holes and the air flow temp was about OAT (which is good).



Now let's run this configuration for a while and report back on say 1 April to see what has happened.



I do think there are different voltage values for manual trannys and auto trannys. Not sure exactely what yet, but I think the pin #23 voltages are different.



Bob Weis

 

[mhenon]

I clear my codes with a Smarty... . Bob Weis

I didn't realize you could clear your own codes. Well, that makes it easier. I would start at say . 525v and work up from there, Most DC APPS come with a figure close to that. If you still get a low voltage code bump to . 550 then . 575 and . 600. Give each number a test and see if it throws a code. At some point the APPS and ECM will be happy with each other.

Keep us informed as there might be some different adjustments between the manual APPS and Auto APPS (manual & auto transmission).

Mike

 

[KarlC]

Bob, when I was doing the voltage testing with the APPS unplugged it threw codes, as expected. I don't have a scanner to clear them, but they have always cleared after 3 or 4 engine starts. Maybe this has something to do with it.