03-04 5.7L APPS obsolete

[Recoil]

Thanks for the update MrFixIt... Do you think this is what is causing the issue you are having when braking to a stop?

 

[MrFixIt]

Well. Keeping my troubleshooting pretty open right now. I'd say the symptom is rooted in the torque converter or engine downshift or PLC and less in the engine or idle or throttle body. We have the one major symptom and several surrounding techniques as follows:

When the truck slows to a stop on it's own with no pedal being touched, such as going up a hill slightly to stop. There is no problem with the vehicle.

When just sitting and idling from a cold start the engine idles for about a minute at 450 RPM then stalls, might be too rich of an idle.

When the engine is idling with a warm engine the idle settles in about 500-550 RPM and keeps running for defrosting the windows, etc.

When driving, the engine runs fine. As a side note: Downshifting seems a bit delayed as I have to press pretty far down and then it shifts from 5th to 2nd in one jump even at 60-65 MPH, the RPM protect comes on at 5500 RPM until the tranny shifts to 3rd at 3200RPM and as I let off it goes through 4th to 5th very quickly. I can hold it at 4th by turning overdrive off.

When driving, slowing to a light or stop sign, at 5-6 seconds the Lightning bolt illuminates and after about 5 seconds of that the engine will stall. Release the brake before the light illuminates or before the engine gets to about 400 PRM; the vehicle will drive normal again. Turn the steering wheel in the second 5 seconds with the light illuminated and the engine stalls immediately.

The way I drive it is if I press the brake pedal, I count to 4, release the brake and re-apply. Other than surging to slow the vehicle, it drives normally.

So, I plan to have an electronic device made to flicker the brake switch for 100msec every 4-5 seconds and see if that is a remedy. I'll update after I install that in a month or so.

Thanks for reading, Mr. Fix It, WA

 

[Recoil]

Are you getting any codes? Are you able to test the transmission control module (the BCM)?

I know this would take more than one person (and probably perfect timing), but can you try to get a code reading when the issue is happening and the red lightning bolt is on?

 

[MrFixIt]

Are you getting any codes? Are you able to test the transmission control module (the BCM)?

I know this would take more than one person (and probably perfect timing), but can you try to get a code reading when the issue is happening and the red lightning bolt is on?

Great idea. I'll try to get the active code during the stall. might take a few restarts.

 

[dblagbro]

I just completed testing on a 2nd 2003 Dodge RAM 1500 5.7L SLT that had a bad one of these with replacement using a new harness wire and an Accelerator Pedal Position Sensor from a Mercedes that is still regularly orderable. I am making a kit with instructions for the replacement. I'll post the eBay link here shortly but this is now something that can be replaced with a retro-fit kit.

 

[dblagbro]

The APPS part kit is now available here:

Dodge RAM APPS Retrofit Kit – replaces 53032456AE & 53032455AD

Upgrade your vehicle with our OEM-quality APPS retrofit kit compatible with part numbers 53032456AE and 53032455AD.

www.voipguru.org

 

[Blacksmith1]

Anyone try this kit?

 

[Blacksmith1]

Ordered it, already shipped. Let y'all know how it works.

 

[UncleGunns]

@Blacksmith1, these APP sensors hardly ever go bad. Unless you have issues with corrosion on wires/ cables from environmental causes etc. or have submerged the front end of the truck, there's likely another issue. Have you scanned for P-series codes for the APPS? Have you monitored the real-time data for the voltage sweeps?

APPS1 signal voltage should run from ~0.4VDC at 0% throttle to ~4.3VDC at 100% throttle with a smooth incline that matches your input on the gas pedal.
APPS2 signal voltage should run from ~0.2VDC at 0% --> ~2.4VDC @ 100%. Same smooth incline, WITH ONE EXCEPTION: The PCM performs a circuit integrity check every ~300ms on the APPS2 circuit. You'll see this as a dropout to 0VDC.

You can have a ton of different issues that activate the link light on the dash. Most are related to poor electrical connections, bad connectors, poor grounding, etc.

The APPS sensor shares 5V and ground circuits with multiple other sensors.

Did you scan and pull any codes for the APPS sensor? If you're seeing the data below without anomalies, your existing sensor is probably good. I'm interested to hear back from you on the original condition/ concern, your diag, and the results fo the new APP sensor.

 

[Blacksmith1]

I put the new unit in. Easy swap, great kit. I now have a new/better code reader. Trying to learn how to use all it's features.
We have replaced the apps, throttle body, injectors, and ECU. The truck wouldn't run at all with the new ECU so I put the old one back in. It ran poorly. After the reset it runs like it has a massive vacuum leak. Dies at idle, doesn't want to rev, dies at any rpm when I hit the brake.
I REALLY miss the '50 Chevy 3100 I had as a young man. So much easier to diagnose and fix.

 

[Blacksmith1]

Oh yeah, now the lighting bolt flashes from the time you turn the key instead of being solidly on after a mile or so.

 

[Recoil]

The APPS part kit is now available here:

Dodge RAM APPS Retrofit Kit – replaces 53032456AE & 53032455AD

Upgrade your vehicle with our OEM-quality APPS retrofit kit compatible with part numbers 53032456AE and 53032455AD.

www.voipguru.org

Thanks for this!

 

[dblagbro]

I just completed testing on a 2nd 2003 Dodge RAM 1500 5.7L SLT that had a bad one of these with replacement using a new harness wire and an Accelerator Pedal Position Sensor from a Mercedes that is still regularly orderable. I am making a kit with instructions for the replacement. I'll post the eBay link here shortly but this is now something that can be replaced with a retro-fit kit.

I have the kit available here now: https://www.voipguru.org/dodge-ram-apps-53032456AE/

Also it's on eBay too (but they charge so much in listing fees that it's cheaper above) https://www.ebay.com/itm/276778199031