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

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Engine/Transmission (1994 - 1998) 1997 dodge plug in cab

2nd Gen Non-Engine/Transmission cb antenna

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How do you get that wedge out Tim. I don't need to do it but mine sounded like it "snapped" in place and I'm not sure how to un-do it!

Mike



I took a o-ring pick with the 120 deg end, and ground it to catch the slot in the wedge. Gary's right my photograghy sucks:-laf but this should show it.
 
I agree that the only thing left is for me to switch 2 & 6. However, I do have the bus APPS fully functional and connected. I will ohm out the IVS and since I have BOTH the bus APPS with IVS AND the MS IVS wired up to plugs it should pop right up what is wrong.



I will have time tommorrow to get this right. Odd how different schmatics are different. I only hope that different years are not different 1&2, 1&6 / 1&6, 1&2. I sure hope not.



At least it is nice and warm and no snow while I am doing this :)



Bob Weis



Gary you have a pm
 
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WOW!!!!!!!! That schematic is just opposite on 2+6 from the one posted earlier!!!! That means Gary and I got ***** lucky and Bob has been BEATING his head against the wall trying to get rid of the 121 code. UNBELIEVABLE THE 2 SCHEMATICS ARE DIFFERENT!!



Mike, out of curiosity, what labeling does your ECM schematic show as to date and part #? Here's a pic of mine:



#ad




It's amazing to me the schematic line labeling is different between your schematic and mine - the line terminations at the ECM are the same, APPS pin numbers as compared to the ECM pin numbers, only the idle/off idle labeling is switched!
 
I did not crank the voltage up because by the time the MS throws, the bell crank has rotated to about . 600 volts and the IVS for throttle up is . 675 for the ECM. It just goes flat for a few more degrees at the bottom. The top end (WOT) is a good 3. 6 volts.



I'm going to run it this way for a while. The reset procedure I think compensates for what the voltage at idle is. Theoretically my idle rpm should be low, it is right on at 850 rpm even at . 440 volts vs the dc APPS of . 600.



Bob Weis



Wire swap day tommorrow :rolleyes:
 
WELL, since Mike has double-checked his wiring, I'd suspect HIS schematic is correct, and I just screwed up (and got LUCKY) in wiring mine backwards!



NOT my usual line of luck if that's the case - but I gotta check and find out! :-laf:-laf
 
WOW!!!!!!!! That schematic is just opposite on 2+6 from the one posted earlier!!!! That means Gary and I got ***** lucky and Bob has been BEATING his head against the wall trying to get rid of the 121 code. UNBELIEVABLE THE 2 SCHEMATICS ARE DIFFERENT!!



The IVS switches to ground, but one potential for confusion is that the diagrams don't say whether the idle or off-idle "signal" is supposed to be low or high (ground or 5V). So both schematics could be right -- one actuated by a switch closing to ground and the other actuated by a logic signal going to 5 volts (opening the switch to ground). Pins 6 and 2 would have opposite wiring depending on the convention used. The fact that these diagrams don't say what they're talking about is very confusing. I work in electronics and this kind of stuff comes up a lot. Frustrating. #@$%!



I did some testing on my truck. With key on, engine not running, and a working DC APPS installed: pin 6 was near ground at idle and +5V when off idle. Pin 2 did the opposite.



The DC APPS pot voltage at the point when the IVS changes state is 0. 76 volts when speeding up, and 0. 72 volts when slowing down. As a reference, this APPS calibration voltage is 0. 620V. For those having trouble, I wonder how sensitive the ECM is to the voltage coming from the pot at the point when the IVS changes state.



Karl
 
I pulled this off an old Geno's Garage web-page. Looks like it's for a 2000 engine:#ad


The web-page had both Ram and non Ram ISB schematics:ECM details for 1998-2002 Dodge Ram trucks with 24 Valve Cummins diesel engine



Weirdly interesting - one of the schematics you point to, shows the APPS switching as you posted earlier, and the OTHER one shows THIS diagram, which is like mine, but uses letters instead of numbers for pins:



#ad




Makes me wonder if a schematic draftsman screwed up with labeling somewhere along the line, and no one noticed...
 
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The IVS switches to ground, but one potential for confusion is that the diagrams don't say whether the idle or off-idle "signal" is supposed to be low or high (ground or 5V). So both schematics could be right -- one actuated by a switch closing to ground and the other actuated by a logic signal going to 5 volts (opening the switch to ground). Pins 6 and 2 would have opposite wiring depending on the convention used.



I wondered the same thing when this issue first came up, but hated to get something started I was unfamiliar with.



At least, as far as the MS IVS setups are concerned, the worse that happens is it won't work, and you switch leads - a bit different with the electronic-based setups...
 
Well, at least out of my frustration something was contributed.



With the MS IVS it becomes very much easier to just swap the leads and NOT worry about IF the circuitry has a malfunction.



Bob Weis
 
... Wire swap day tommorrow :rolleyes:



I don't think that's going to do anything for you other than throw a code and default to idle. It's possible (I guess!!) that pins 2 & 6 are interchangeable and the ECM will figure out which way to go during the learning (key on. . pedal down) phase but... ..... Let us know how that goes Bob.
 
OK, I couldn't stand the suspense, and dug in and checked to verify APPS pin functions, and MIKE'S schematic is correct! I have NO idea how I managed to screw up, and using the WRONG schematic, still got mine wired correctly in spite of myself! :rolleyes::-laf



Pins #1 and #6 are definitely in the CLOSED position at engine idle, and switch to #1 and # 2 CLOSED off-idle - as Mike's schematic indicates:



#ad




Much appreciation to Mike for providing the RIGHT schematic, sure dunno where the wrong one originated - someone else's error I guess! I'll now go back and correct all the previous WRONG schematics I have posted and replace them with the right one!
 
YOU CAN ONLY HAVE 5 OF THESE Oo. Oo. Oo. Oo. Oo.



If the 2 and 6 are swapped you get a 0121 and there are apparently different severities of codes. With a 0121 it will not accelerate, with a low voltage code it will accelerate, just needs recalibration, etc.



If you have the APPS pot wired right but the IVS wired wrong you will get the MIL after engine start 0121. Doesn't mean your APPS pot is not right, or it needs calibration, your MS is wired wrong.



Swapped the MS wiring (blue and red) and it is fine.



I have been thinking what happened and how do we keep the same thing from happening to others. I tried painting the different wires with different color nail polish colors to help keep the right wire going to the right place. Does not work because as soon as the nail polish dries hard and the wire flexes the nail polish color paint identification you are using cracks and falls off. It does work for the connector bodies though. My APPS pot connector is red, the IVS connector is green. Who would wear green nail polish?



Then I tried using different counts of small zip ties. 1 zip tie for ground, 2 zip ties for idle, 3 zip ties for throttle. Not a bad system, but I managed to screw that up. Then I went down and bought the right color wire for the MS, black, blue, red (I get marine grade wire at West Marine because it is tinned for corrosion protection). That worked. Instead of having (WeatherHead connectors) 3 back wires with (or with out) nail polish identification, you have the correct color coded wire.



The second point I want to make is make sure you know the pattern of the connector. The bus APPS IVS is ground, idle, throttle. Not ground, idle, not idle. Not ground, idle, off idle. Ground, Idle, Throttle (dc pins 1,6,2). Right here is THE CATCH. Everything is ground, idle throttle, EXCEPT dc, The APPS harness for IVS is pin 1 GROUND, then pin 6 IDLE, then pin 2 THROTTLE, for ground, idle, throttle. The WeatherHead A, B, C for ground, idle, throttle.



Now on the Weatherhead from the MS. The MS is black ground, blue idle, red throttle so keep the pattern the same, ground, idle, throttle (WeatherHead A,B,C)



If you use the bus APPS harness the IVS is orange, blue, green. It comes out in a WeatherHead connector Orange (A), Blue (B), Green (C) guess what?, Ground, Idle, Throttle. Same pattern.



I think where I got screwed up is the picture on the side of the MS. It shows Red has contact, Blue does not have contact, and Black is common. Now is that before the switch is activated (ie as it sits in your hand) or is that after the switch is activated (you close the MS switch contacts)? Well, RED is THROTTLE (which means after the switch has relaxed (like it lays in your hand)). However the same pattern, black is ground, blue (next) is idle, and last is red is throttle. SAME PATTERN Ground, idle, throttle.



Then it is easy to take the black, blue, red (ground, idle, throttle) and mate it to a WeatherHead connector A (ground), B (idle), C (throttle).



Just keept the pattern the same, Just keept the pattern the same, Just keept the pattern the same.



One very happy camper. Bus APPS pot, ventilated APPS pot, MS IVS (with bus APPS IVS backup ready, plug and play).



Bob Weis
 
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WELL, with my setup, I'm pretty sure I tried (without proper thought!), using the Normally Closed (NC) and Normally Open (NO) leads as the MS is lying on the desk - when in FACT, those leads are REVERSED with the MS actually installed as we are doing - the MS in OUR application, is installed against the belcrank so it's "NC" position actually becomes it's "NO" position, then the accelerator is depressed, and the MS switches...



Just dumb luck on my part! :-laf:-laf



Thankfully, SOMETIMES, 2 wrongs DO make a RIGHT! :-laf
 
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Well, we prevailed regardless of how smart we thought we were at the time.



That's why we need to get some time on these fixes to time prove them as well. However, I do feel really good about what we are doing, and feel we have found / manufactured a permanent fix to the APPS and can duplicate the fix as well.



One less significant component that can go wrong. ;)



Bob Weis
 
YOU CAN ONLY HAVE 5 OF THESE Oo. Oo. Oo. Oo. Oo.



If the 2 and 6 are swapped you get a 0121 and there are apparently different severities of codes. With a 0121 it will not accelerate, with a low voltage code it will accelerate, just needs recalibration, etc.



Again, I'm am sorry Bob! When you posted that the MS was giving you a fit i knew something HAD to be up with the wiring, thats when i double checked mine. At least you learned a couple of things along the way,just to bad it was the HARD way.
 
Well, we prevailed regardless of how smart we thought we were at the time.



That's why we need to get some time on these fixes to time prove them as well. However, I do feel really good about what we are doing, and feel we have found / manufactured a permanent fix to the APPS and can duplicate the fix as well.



One less significant component that can go wrong. ;)



Bob Weis



I'm amazed it ran at all with the wires crossed Bob. Damn Cummins ECM is smarter than all of us. Glad you got it working. Your glitch was driving me crazy too.

When I first hooked up my Williams APPS I couldn't get it above an idle. That was three months ago and we were headed on a long road trip so I didn't have time to sniff it out. As soon as I got home I caught my mistake and the thing ran fine. Yeah. . this wiring maze, going from OEM color codes & pins 123456 to Williams color codes & pins A B C / A B C was confusing to say the least. I'm not going to admit how many times I soldered up those weather pack pins only to find out I had male connector going into male connector or vise-versa. Then fixing that to realize I had male IVS going to female TPS. Made me nuts!!!

Anyway, looks like we're running on all six cylinders now. Great job!!!

Mike
 
. . Much appreciation to Mike for providing the RIGHT schematic, sure dunno where the wrong one originated - someone else's error I guess! I'll now go back and correct all the previous WRONG schematics I have posted and replace them with the right one!



Gary. . don't want to take tooo much credit for that schematic. I'm sure I Googled "Dodge/Cummins ECM" or some such thing and that was the first to pop up!!!!
 
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