I didn't take it that way. I knew what you were saying..

 

I got this page because I was searching for the APPS because I want to make a high idler. Looks like I can do that just by messing with the voltage input to the PCM.

Anyway I was curious about this article, so I checked the 23 pin and I was at a lowly .30 volts. I took off the APPS and it called for .519 volts. I was able to adjust it to get it to .50 v. I couldn't quite get it to .519, but I figure .50 is better than .30, right? Question is what on earth does this accomplish?

My "Malfunction Indicator Lamp" is now lit... so, the other question is what did I break??? I had the C1 connector unplugged from the PCM while I was making the adjustments so I could constantly check the output voltage. I figure the PCM was probably wondering where a few of its input levels were and tripped the light but I was hoping when it got them back it would shut up.

 

I had a check engine light also that I cleared. It was a p0602 =over fueling from the newly matched voltage. The new IAT sensor fixed the code And I had a ABS and brake light on and they quit once I drove the truck down the driveway. IMO the PCM is "made" to conduct information most reliably and consistently when working with in these voltage parameters. The fastest way to burn any thing electrical out...is feed it low voltage! Not so much in circuit boards as in bulbs, but it sure isnt helping any thing.

 

I was sitting there with no voltage for the entire C1 connector for 30 minutes ... I did this so I could adjust the APPS then read it quickly. I guess I could've burned out the entire PCM. Not sure what to do now. I tried taking both + and - terminals off and letting it sit for a while but that didn't do any good. I don't think that having NO voltage should break the PCM. Incorrect voltage I can understand but no voltage should not have hurt it I don't think. Also, I did not remove/replace the C1 connector with the ignition on, only when the ignition was OFF. I also got the ABS light, and that also did go away after I drove around.

 

Alright.

I did the old on/off on/off deal and i got no codes except for 1693 (doesn't it always read 1693?) and then the light went away. Time for a beer now--sometimes I scare the crap out of myself!

So back to the original question, by calibrating the idle voltage to the proper voltage, what should I expect to see. What exactly did I accomplish by re-calibrating this?

 

Walt the MAd ecm will cause the p602 also. I also cleared codes after adjustment and Have burned a 1/2 tank with no issues.

 

Anyone have the APPS fail them? If so what happens? Mine is currently putting out 4 V at idle when it should be reading 0.5 V. The wait to start light is now Flashing (Definitely Not going to try to start the truck).

 

If you do start it it will redline at that voltage, being it is high try to do what is ststed above and lower the idle voltage to . 543 or what ever is on the sensor tag.

 

Oh yeah. I am not starting it. I don't think it'll even let me but I'm not going to. Gotta figure out what I did.

 

so you tried to calibrate and ended up with 4 volts??, maybe when you tightened down the torx bolts you moved the sensor.

 

I was able to calibrate it no problem. I was sitting at like .3X volts and brought it up to .51 (tag says .519). Heck I am pretty excited to see how it drives after a drastic change like that!

Anyway - I put a resistor hooked up to a switch and tested it in the engine bay. A 125 ohm resistor hooked up to the sensor ground brought the voltage from .51 up to .70 volts. The point was to get a high idle at the touch of a switch. Well after I wired it all up nice and neat with heat shrink and split loom and an in-cab switch, something went wrong.

Not sure if it was the plugging/unplugging of the APPS a few times while the ignition was *ON* or maybe bad wiring (grounded somewhere?).

Either way I'll have to check it out. First step tomorrow will be to take off all my nice wiring and re-connect the #4 wire on the APPS directly (by passing all my wiring) and see if that fixes it.

If I had known I was going to be buying a $350 APPS, I would have just gotten the $200 high idle kit

 

$350 for an apps sounds cheap I thought someone had said they where more than that, anyway hope you find your problem, I bought the high idle switch about 3 years ago it is a great tool and the reason I bought mine is you can adjust the rpm to your desired choice.

 

PN on the throttle cable is 53031626AC this is for all models 5.9 diesel 24 valve (so 98.5-02 I'm guessing). $40 shipped to my house. Took about 15-20 minutes to get in, very easy. Nice piece of mind not having a fraying throttle cable.

 

My truck recently threw the P0122-TPS voltage low code. Is it possible to recalibrate my existing TPS or do I need to replace it? My truck is running like you-know-what!

 

absolutely - check the link posted to the dieseltrans.com article and follow the steps -- pretty simple.