This truck...no pedal untill warm
 

So this freaking truck. Iv got this 2004 3500 6 speed right. well couple weeks ago pedal want dead and threw the codes P2127-P2123-P2128-P2121- AND P2122. So i replaced the APPS witch mine was under the Battery tray, reset the pedal and it worked for about half a day, now looking on this forum and geting advice i went threw the intire harness to the ECM and had redone the grounds and power cables. worked for a bit longer this time then code agian, dead pedal. now this is what i have relized. when i start the truck it has a dead pedal, I let it warm up and she runs like a rape ape.. but when she cools back down nothing. as soon as the temp gauge moves past 140 shes good to go the light will even go off..

ANY ADVICE IN WHAT TO LOOK FOR NEXT, TRYING TO TRADE THIS THING IN AND WONT GET ANYTHING FOR IT IN THIS CONDITION

And forgot to mention the temp here is a daily of 90degrees. so its not sitting in below conditions

I'd start with 2 cheap approaches:

If available (at home, no cost) I'd replace the battery- if it's OK then, time for new batteries.

if available- check AC voltage across battery terminals- should be very low- anything above 0.3V points towards alternator brushes or battery to me.

It looks like your throttle position sensor throws codes for being high and low for each pin, so my suspect would be the supply voltage for the sensor fluctuating.

so when checking AC voltage Im guessing the truck should be running. I just did and it really didnt give me a set reading. just bounced all over the place. and also what should the ALT be pushing

OK, AC readings all over the place- not good!

You can try to disconnect the alternator by removing the 140A fuse from the PDC and try running the truck from the battery only. (Naturally this won't do for long, but it shows if the alternator is the culprit)

If it works with the alt disconnected, take a look at the alt brushes- can be had from fostertrucks.com for example.

The alternator should not push AC, but usually does a small amount which is cancelled by the batteries. If the diodes or the brushes are bad, there is too much AC for the batteries to cancel out and you get weird behaviour when you need much electrical power. (EG intake heater, fuel heater..)

I believe you want the AC voltage to be no more than .035 volts or 35 milivolts

Ok so that had no diffrence. here is what its doing today. start up and only has pedal up to 1500rpm. Then if i hold it to the floor for about 10 seconds at 1500rpm and let off and hit it agian, it has full pedal for a couple seconds but then dies back down to nothing. but as before once the truck is warm past 140 she runs like a top.

OK, now it looks like there could be a problem of the temp sensor pulling down the voltage of the +5V supply to the APPS..

(Or it could be the ECM.. maybe get a code reader that can show you realtime data)

I have a SnapOn Verus for the live data. what should i be looking for on the data.

and also new codejust came up P0107...

Again something pointing to the +5V supply from the ECM to the sensors.

You'll need to look for a chafed cable or a defective sensor shorting out.

With your scanner check the cold truck engine off for the plausibility of the following parameters:

Coolant temp
Intake air temp
Manifold absolute pressure
Battery voltage
Throttle position

See if those values change when you move the throttle pedal (only throttle pos should change, and go up to close to 100% at WOT)

Then start the engine, see if the values start to fluctuate wildly or become unplausible right after startup.
Let the engine get close to the "good warm" state and keep your eyes peeled on what changes when the temp goes over this threshold.

Or you could start by checking out if +5V is present on the sensor supply- if not, or below 5V start wiggling wires and see if that changes anything, if not start unplugging sensors until you find the one that lets the voltage come up when being unplugged.

Ok so checking the temp sensor V first i got 4.88v key turned over no running.

Truck completely cold and its about 80 degrees out today Verus says coolant temp 104 and 2.4volts
IAT temp 102 and .9v
ECM voltage 12.4
MAP 29.23
Throttle Position
APPS1 voltage .43 5%
APPS2 voltage .21 5%

key off WOT everything stays the same excapt BARO PRES


And after dooing all that uncludeing looking at the Temp Sensor wire, i noticed it looked like somone had left the sensor pluged in and screwed it in. so i undid it and when i started it this time i have full throttle and no dead spots

On a sunny day the temp values are plausible. (IAT heats up faster than coolant (goes with the engine block) if standing in the sun.
Finding the damaged cable is good- maybe even the APPS wasn't strictly necessary..


So, let's conclude it is solved, with minimal material investment :cool:

Instead of trading it in, I would try to post it in the classifieds here (and maybe on some other sites)

[QUOTE=AlpineRAM;3349557]On a sunny day the temp values are plausible. (IAT heats up faster than coolant (goes with the engine block) if standing in the sun.
Finding the damaged cable is good- maybe even the APPS wasn't strictly necessary..


So, let's conclude it is solved, with minimal material investment :cool:

Instead of trading it in, I would try to post it in the classifieds here (and maybe on some other sites)

Yeah maybe.. hopefully.. im letting it site at work over the weekend we will see monday morning.
And thank you for replaying. I read threw some other forums before i posted and was really hoping you would replay. thank you again