Engine/Transmission (1998.5 - 2002) Here we go again...APPS

[DLBurns]

OK... I am into this problem $600 bucks, 2 new Optimas and a new APPS and I am still getting the CEL and thowing the P-1023 code

WTF

Where do I look now? the miss is really intermittent, disconnected the batteries overnight and re calibrated the APPS, drove the truck over to Sonora yesterday from Arnold and back and it never hesitated once?? but the code and CEL are still there?

I can't begin to describe how frustrated this thing is making me!

Could it be a problem with my PCM?? I have cleaned every connection and ground that I can get to. Am I gonna have to break down and take it to the dealer??

Need some suggestions from those in the know!! I am ready to run it off a cliff

Dave

 

[BPINE]

Any input guys ?

 

[DLBurns]

Update, drove it all day on Saturday with no code or CEL, started home this morning and turned my selector to defrost and it thru the code and CEL

Also have no cruise control now, the light doesn't even light up on the dash?

Although the CEL is lit and there is the P-0123 & P-1693 codes I didn't experience any hesistaion or miss on my 160 mile trip home today... and I was driving the balls off of it!

Gotta be some folks out there who have delt with this???

 

[FourBarR]

dumb question, you are not mis interperting the t/q locking and unlocking for a miss are you?i had a similar problem ,did all the things you did , problem not fixed. ordered a filter from dtt for the apps. problem solved. noise in the wiring harness causes this . d/c found it in their wizdom to put the apps wires in the same bundle with other high energy wiring. just trying to help . good luck with it

 

[Bob4x4]

Check the wiring to the pcm and the connector at the pcm. Is the voltage the same at the ecm and the pcm?



Bob

 

[DLBurns]

Four Bar, Not the TC locking and un locking ( although it is doing that also

I am going to look into the DTT filter and the HappiBox and see if I can cure that problem at least ) P-0123 code is "switch A circuit high input for the APPS"



Bob,

Have not checked the voltage at the PCM and ECM... thanks for the suggestion



Having no cruise all of a sudden may have something to do with the problem as that is directly related to the APPS. When I lost the cruise before it was just the vacuum line under the battery that came off, the cruise light would still come on on the dash, now it doesn't



Keep the ideas coming fellas as I am totally lost here!!



Thanks

Dave

 

[Sick Boy]

same here i replaced apps an my cruise still not workin light will come on for cruise but when u hit set the light does out? heard that there is servos :{ that go bad under driver side batt.

 

[DLBurns]

Any more ideas to try and solve this problem???

We are going to hook up an ODB II scanner to it this weekend and see what that tells us? I have been reading of some problems with the Edge EZ boxes going bad, would this cause this problem??

I'm just grabbing at straws here guys as I have no idea what is causing this problem.

Any ideas or suggestions would sure be appreciated.

 

[2-ND TIME]

APPS how many have bad APPS and don't know it ???

The APPS I think that the idle , off-idle is the bad component for my do_g_ 99 Cummins wiring diagram for 99 model year #3666480 specifies that the contact resistance should be <125 ohms and open circuit resistnce of >100K ohms so that mine measures 2,640,000 ohms and the ecm doesn't see a change of state so fuels accordingly to the idle fuel and revs ( like a jimmy) but no more power out of it little boost till 4 th gear and over 1500 rpm then labours hard to get going. What junk!

 

[tgee]

The APPS has idle validation switches in it, there to tell ecm whether you are giving it the gas or not. The reason for this is there has been incidences of electronic throttle sensors giving false signals, increasing RPMs on thier own, usually caused by moisture or electrical noise in the wires. I think the concept of this makes sense, and not all applications of electronic engines used this feature, but I think it is now a standard of the industry. I just wish the Dodge APPS wasn't so darn expensive!

 

[DLBurns]

Update... . we connected a Snap On MT2500 scanner to the truck yesterday cleared the old codes ( P-0122 & P-0123 ) and went for a long ride. Everything was great with the truck and voltage to the APPS was consistent with what my right foot was doing to the accelerator. Switched on the AC, bingo!!! CEL comes on and engine stumbles every time the AC compressor cycles. APPS volts go immediately to 4. 98 and then back to normal when compressor cycles off. No cruise control or light on the dash when CEL is lighted. Pulled over and disconnected the EZ box, drove another 10 miles or so, no change. Still get the stumble with AC on and no stumble with AC off. Hooked the EZ box back up and cleared the codes again. Disconnected plug to AC compressor and took off for home and. No CEL or stumble and volts consistent with acceleration, switched on the AC and got the CEL and stumble??? no AC cycling as the plug is disconnected??

I need some more ideas here... . it is directly related to the AC somehow, what am I looking for? a bad ground, bad PCM ????

Where do I go from here guys???

Dave

 

[tgee]

Seems like bad ground, according to my almost worthless service manual wiring diagrams, A/C clutch, fuel transfer pump, Cummins bus, fuel heater share the same ground. Also read someones post here about regrounding the apps direct to battery, black and yellow wire at apps.

 

[DLBurns]

I checked my service manual wiring diagrams also... may as well have been written in Chinese as I can't decipher a damn thing out of them.

Cleaned the ground at the PCM and the engine ground on the passenger side of the block ( how many grounds does this thing have ??) as well as the PCM connectors and the AC/Heater relay in the PDC..... fired it up ans switched on the AC... ... same problem

I am currently soliciting the RamRunners members for use of there PCM for an hour or so to verify that the problem is there.



Anybody know how much a new PCM goes for??

 

[Big White Beast]

Update... . we connected a Snap On MT2500 scanner to the truck yesterday cleared the old codes ( P-0122 & P-0123 ) and went for a long ride. Everything was great with the truck and voltage to the APPS was consistent with what my right foot was doing to the accelerator. Switched on the AC, bingo!!! CEL comes on and engine stumbles every time the AC compressor cycles. APPS volts go immediately to 4. 98 and then back to normal when compressor cycles off. No cruise control or light on the dash when CEL is lighted. Pulled over and disconnected the EZ box, drove another 10 miles or so, no change. Still get the stumble with AC on and no stumble with AC off. Hooked the EZ box back up and cleared the codes again. Disconnected plug to AC compressor and took off for home and. No CEL or stumble and volts consistent with acceleration, switched on the AC and got the CEL and stumble??? no AC cycling as the plug is disconnected??

I need some more ideas here... . it is directly related to the AC somehow, what am I looking for? a bad ground, bad PCM ????

Where do I go from here guys???

Dave

Thanks for the heads up. My problems seem transmission related but throw the same code. No CEL for me just the 0123 code.



After reading this post I had a hunch, seems when I adjusted the TPS I had the AC shut off, truck ran great and after several runs no codes. Then I drove it later in the day when it was warmer and turned the AC on and it started screwing up again. Bingo!



Talked to the Dodge dealer for what that's worth. Seem when the AC is turned on theres a singnal sent to the engine to compensate for the extra load. How and where eludes them but that has to be what's causing it.



I had a voltmeter in the cab watching the APPS to PCM voltage and no great change either with AC on or off, it followed the pedal and never overvolted. So this tells me it's probably the signal to the ECM. Now does it do this through the APPS and that's why that code or ????.



I'm lost after this. Someone suggested checking the batteries, I cleaned the terminals and tested running volts at 13. 8 so that's about right. Next to get a load test on them.



Garrett

 

[Bob4x4]

Thanks for the heads up. My problems seem transmission related but throw the same code. No CEL for me just the 0123 code.



After reading this post I had a hunch, seems when I adjusted the TPS I had the AC shut off, truck ran great and after several runs no codes. Then I drove it later in the day when it was warmer and turned the AC on and it started screwing up again. Bingo!



Talked to the Dodge dealer for what that's worth. Seem when the AC is turned on theres a singnal sent to the engine to compensate for the extra load. How and where eludes them but that has to be what's causing it.



I had a voltmeter in the cab watching the APPS to PCM voltage and no great change either with AC on or off, it followed the pedal and never overvolted. So this tells me it's probably the signal to the ECM. Now does it do this through the APPS and that's why that code or ????.



I'm lost after this. Someone suggested checking the batteries, I cleaned the terminals and tested running volts at 13. 8 so that's about right. Next to get a load test on them.



Garrett

Don't ask why,but I have seen this issue fixed with a clockspring.



Bob

 

[PC12Driver]

Talked to the Dodge dealer for what that's worth. Seem when the AC is turned on theres a singnal sent to the engine to compensate for the extra load. How and where eludes them but that has to be what's causing it.

Garrett

I'd buy that on a gasser, but the governor (ECM) on our diesels will automatically boost fuel to maintain an RPM. There isn't a reason for the idle-up signal on our engines. Probably why the "how and where" eludes the dealer.

 

[2-ND TIME]

Apps

Well it would be good to be able to read the different postings and comment on some of what is written. Lets see when I put my apps on an oscilloscope I was getting voltages from millivolts 0. 158, 0. 173 then next one was 11. 48 volts for I had to change scales on the scope to read then then back to milli volts again. I have a bad bucking from 1100 to 1275 rpm and very hard to drive below 1600 rpm. The sync pulse was badly corrupted , they were all bad except the ahhhh pin ? two of the positive and neg pulses. The grounds measured all in the milli ohm range but they were cleaned and improved on. When the lift pump wasn't working for some 8 months the problems were still there and didn't change.