Intermittent Dead Pedal

C

Cummins 5.9

New member
Joined
Jan 3, 2020
Messages
8
hi guys im new to the forum I have 2005 dodge cummins 5.9 that has 420klm im having issues with dead pedal (cuts in and out) rpm spikes in park at idle! the cold start fast idle feature cuts out prematurely! when driving truck and pedal starts acting up sometimes i pull over shut of pull key restart and its like nothing happened! recently swapped the apps sensor with pedal and did the reset and no change! any help would be much appreciated !
 
Check apps sensor voltage via scanner. There are two sensors on your pedal. You by nature have two voltages on the pedal (apps) that averages out. Both start at about 5v and their value is measured by the ecm.


What was wrong with your other pedal?
Any DTCs?


You may have another issue going on there.
 
Last edited:
intermittent dead pedal

at this point dont think anything wrong with my other pedal! im getting codes p2121 p2122 p2127
 
Last edited:
Sounding like grounds, or a schizophrenic ECM.
I'd lean towards ecm is going loony.

Mark.
 
Mark Nixon said:
Sounding like grounds, or a schizophrenic ECM.
I'd lean towards ecm is going loony.

Mark.
Click to expand...

^^^^

Check ALL and I mean ALL your battery cables. Make sure they are clean. Check the grounds to the engine and body too.

Make sure your batteries are good as well.

I have had to on some trucks add ground leads before to get rid of little gremlins. Mostly on 06 trucks for one reason or another.


For your reference:
P2121-PPS CONFORMANCE ERROR
P2122-PPS 1 VOLTAGE TOO LOW
P2127-PPS 2 VOLTAGE TOO LOW

The plug pinout for your truck at the pedal is:
CAV-- CIRCUIT--------- FUNCTION
1----- F856 20YL/PK----- 5 VOLT SUPPLY
2----- K29 20WT/BR----- APPS NO. 2 SIGNAL
3----- K400 20BR/VT----- APPS NO. 2 RETURN
4----- K167 20BR/YL----- APPS NO. 1 RETURN
5----- K23 20BR/WT------ APPS NO. 1 SIGNAL
6----- F855 20PK/YL------ 5 VOLT SUPPLY


As Mark stated. I bet your 5v ref signal is low/bad, or dropping out. Check out the wiring from the ECM to the pedal making sure your harness is intact and check resistance for corrosion. If not than the ECM may be the culprit.
 
Last edited:
Another place of concern is the large, C-130(?), connector at the firewall, above the fuel bowl.
This is where the APPS is routed through and can get wet.
If you look at Raychem's color codes, you'll see that the APPS part of the connector is all on one row of this connector.

It wouldn't hurt to see if there's some pin corrosion there, on both plugs.

Also, the ECM plate is NOT grounded to the block, as it has rubber isolators to dampen vibrations to the ECM, yet it does have a ground that's in the harness and can be corroded, or loose.

Mark.
 
intermittent dead pedal

hi guys 2 weeks ago i noticed one battery terminal half melted and melted a hole in the top of battery! put new terminal put new battery ! now today went to plow the yard and drive belt came off tangled up around pulleys and fan! thanks for the info.. i will check that when i get a chance and post updates!
 
hi guys here is an update ! problem solved that was causing my dead pedal and intermittent loss of fuel guage ended up being bad contact in the electrical plug on firewall above fuel filter canister ! thanks guys for the leads !
 
Glad to be of assistance!
Thanks for letting us know the outcome. :cool:

Mark.
 
You must log in or register to reply here.
Back
Top