Adjusting the APPS Voltage

BgBlDodge

Hates hippies
Many have found that correcting the output voltage from the APPS sent to the PCM has increased the throttle response, and boost. This calibration also adjusts the APPS for wear.

Instructions:

Tools: Digital Volt Meter, T-20 Torx bit, #1 phillips, 10mm socket

With the key on, engine off you need to probe the APPS wire to see where the voltage is currently set at.
The best location to probe the wire is on the PCM (Power Control Module) which is located on the passenger firewall behind the air intake.
You want the C1 connector, this is the connector closest to the engine
You want the orange wire with a dark blue tracer which is pin #23 (Please use a suitable backprobing adapter for your meter lead, do not pierce the insulation as this can lead to water intrustion/corrosion.)
Voltage should be somewhere around 0.5 volts,
At this point the voltage reading does not matter, it just has to be accurately written down for later reference

TURN THE IGNITION OFF ON THE TRUCK

Remove the black plastic cover off of your APPS. There are two plastic screws. One on the top and one on the front facing the radiator. It takes a little prying to pull it off.

Undo the 6-10mm bolts that hold the bracketry in place but DO NOT REMOVE THE CABLES!!

You will notice the APPS is on the back of the bracketry that you just removed, it is held in place by 2-T20 torx bit screws. These screws have a little bit of locktite on them so make sure you have a good socket and gently give a little tap with a hammer before attempting to loosen. Be very careful because these screws strip VERY easily and you only get one shot at them (VERY VERY VERY IMPORTANT; They are VERY tight).

On the APPS you will find a white tag that gives you the information on what the APPS voltage should be.
After loosening the screws (do not remove) you can rotate the APPS clockwise or counter clockwise to get the adjustment (towards the front of the truck increases voltage and towards the rear of the truck decreases voltage)
The reading you took at the beginning of the process on pin #23 should match the white tag on your APPS. If it doesn't the adjust accordingly.
 
Thank YOU!! I've reset my APPS 3 in the past 5 days and the TC locking and unlocking crap is still happening! I'm gonna try this to see if I can get it all straightened out.

Also after adjustment do I need to reset the APPS via unhooking the negative battery cables and all that other stuff, or am I good to go by doing this procedure?
 
You should be good to go. I have never had to reset the APPS the other way after adjusting the voltage and I've done half a dozen of them.
 
Well I got my voltage up to .53 and that's as high as I could get it. the sticker on the back says .56 volts. When I checked pin 23 it read .38v, so I figured I fixed it, but it didn't nothing. My TC keeps locking and unlocking like crazy. Any ideas?
 
SuperDave4x4, check your brake pedal switch, it also tells the PCM when to lock and unlock the TC.
BgBlDodge, Nice write up!
 
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