Dead pedal AGAIN!!

[Kevynmurray18]

So I need some help. About 5 months ago I got the dead pedal. Got the codes saying it's bad so I replaced it from timbo and worked for a few hours then it happen again. The next day I replaced all battery terminals and fixed it for a few weeks. Once again dead pedal again. Found out one battery was bad and the other going bad. Replaced both and fixed the issue until now. I'm having dead pedal again and have no clue what's going on. I can't find anything and just need help. It is a 2001 ram 2500 24v with 75hp injectors rebuilt trans all new terminals and batteries. 

[Mopar1973Man]

Need a live data tool and watch the TPS signal to see if dropping out.

 

Might check for error codes using OBDII tool and see if there is any codes pertaining to the APPS sensor.

[Kevynmurray18]

6 minutes ago, Mopar1973Man said:

Need a live data tool and watch the TPS signal to see if dropping out.

 

Might check for error codes using OBDII tool and see if there is any codes pertaining to the APPS sensor.

Alright. If it's dropping out do i replace it ?

[Mopar1973Man]

Not right away no. Need to verify that there isn't a wiring issue or power issue creating the problem. But it really helps to do some diagnostic work to see where the problem is. 

 

I've got to ask do you have an Automatic Transmission? Did you possibly do any modifications to add grounds to the APPS wiring or modify wiring on the engine to resolve TQ converter issues? I've seen people suggest adding grounds to the APPS wiring to the PCM and this might be done wrong or poorly creating issues for your dead pedal. I always highly suggest not to modify any wiring on the engine there is ZERO need for it.

[dripley]

I second @Mopar1973Man's opinion. About 3 yrs back I was having some dead pedal issues and surging issues with APPS codes. Ended up replacing the APPS and the problem stayed with me. I never figured it out but thru messing around in the wiring The dead pedal went away and eventually recently the surging went while messing with the map sensor. The map issue came up after the dead pedal and surging went away. I have no explanation as to how this happened. But it did. As being a member of the electronically challenged I cant explain it. If I could ever get my truck to Mike's house maybe he could figure it out. 

 A bad sensor, battery, alternator, broken ground and on and on will make these trucks do screwy things. Just wish I knew what I did to mine to move problem to the MAP sensor from the other issues. 

[Kevynmurray18]

43 minutes ago, Mopar1973Man said:

Not right away no. Need to verify that there isn't a wiring issue or power issue creating the problem. But it really helps to do some diagnostic work to see where the problem is. 

 

I've got to ask do you have an Automatic Transmission? Did you possibly do any modifications to add grounds to the APPS wiring or modify wiring on the engine to resolve TQ converter issues? I've seen people suggest adding grounds to the APPS wiring to the PCM and this might be done wrong or poorly creating issues for your dead pedal. I always highly suggest not to modify any wiring on the engine there is ZERO need for it.

 It is a automatic. And I have the bd noise isolator and if fixed the surging and lockup problems 

 

29 minutes ago, dripley said:

I second @Mopar1973Man's opinion. About 3 yrs back I was having some dead pedal issues and surging issues with APPS codes. Ended up replacing the APPS and the problem stayed with me. I never figured it out but thru messing around in the wiring The dead pedal went away and eventually recently the surging went while messing with the map sensor. The map issue came up after the dead pedal and surging went away. I have no explanation as to how this happened. But it did. As being a member of the electronically challenged I cant explain it. If I could ever get my truck to Mike's house maybe he could figure it out. 

 A bad sensor, battery, alternator, broken ground and on and on will make these trucks do screwy things. Just wish I knew what I did to mine to move problem to the MAP sensor from the other issues. 

I thought it was the map sensor and replaced it and still nothing. The only thing not replaced it alternator. Should I try that?

[Mopar1973Man]

3 minutes ago, Kevynmurray18 said:

It is a automatic. And I have the bd noise isolator and if fixed the surging and lockup problems 

 

 

Get rid of that filter... Throw it in the trash and fix the real problem which is the alternator. Your APPS problem could now be a AC noise issue or damaged ECM from excessive AC noise. Is there any other wiring modification done?

 

4 minutes ago, Kevynmurray18 said:

The only thing not replaced it alternator. Should I try that?

 

Yes, Most likely. Test the AC noise voltage at the BATT terminal of the alternator running. It should be less than 0.05 AC volts. Make sure to use a quality digital meter that has a 2V or smaller scale AC. 

[Kevynmurray18]

3 minutes ago, Mopar1973Man said:

 

Get rid of that filter... Throw it in the trash and fix the real problem which is the alternator. Your APPS problem could now be a AC noise issue or damaged ECM from excessive AC noise. Is there any other wiring modification done?

 

 

Yes, Most likely. Test the AC noise voltage at the BATT terminal of the alternator running. It should be less than 0.05 AC volts. Make sure to use a quality digital meter that has a 2V or smaller scale AC. 

Alright! Do y'all recommend a alternator from orileys ? 

 

[Mopar1973Man]

Ummm... Well it tough to find a NEW alternator anymore most in the parts stores are all remanufactured. So I HIGHLY suggest you bench test your current alternator first to see if it truly failing. Then the new alternator they pull off the shelf and have that one tested before you even pay for it. 

[dripley]

TEST the alternator first. Dont just run a buy a new. Oriely's, Advance, Auto zone, and many more will sell you a lifetime warranty one that could be putting out to much AC voltage. You have to have them test them before you walk out with it. Theirs are all remans and you dont know what comes out of the box. A lot them dont even know how to test them properly anyway.

[Kevynmurray18]

2 minutes ago, Mopar1973Man said:

Ummm... Well it tough to find a NEW alternator anymore most in the parts stores are all remanufactured. So I HIGHLY suggest you bench test your current alternator first to see if it truly failing. Then the new alternator they pull off the shelf and have that one tested before you even pay for it. 

I had them test it once and they said it was good but before that I took the meter to it And I believe I was getting .22 so I thought that it was weird. 

 

[dripley]

I guess the point I was trying to make originally was that there are things beyond me as to what the real problem is. There were times that I disconnected my batteries to work on something entirely not associated with the surging or dead pedal just to have them gone after putting it back together. The only reason I messed with the map sensor was the odd time I got a MAP code. I had the original MAP sensor and reinstalled it. I broke it installing and put the other one back in. Whatever I messed with stopped the surging. Just wish I knew what it was I touched.

[Dieselfuture]

9 hours ago, Kevynmurray18 said:

Alright! Do y'all recommend a alternator from orileys ? 

 

No, ether rebuild your factory one assuming it is or buy one on line that is new factory replacement or have one built by someone that knows what ac noise is.

[CTcummins24V]

https://www.nationsstarteralternator.com/180-Amp-HP-High-Output-Alternator-for-2000-Dodge-p/13874-180-hp.htm

 

If alternator is the issue, this ^

[Mopar1973Man]

11 hours ago, Kevynmurray18 said:

I had them test it once and they said it was good but before that I took the meter to it And I believe I was getting .22 so I thought that it was weird. 

 

 

Make sure the shop is testing for AC ripple noise. Most shops just check for DC volts and DC AMps as long as it meets the requirement its passing. Now with today's electronics in the vehicle the DC power has to be clean and AC noise free. Lot of stores haven't upgraded test stands. 0.22 is a FAIL and very very damaging. A new or properly working alternator is typically 0.02 to 0.03 AC volts (or 20-30 mV AC).

[Kevynmurray18]

5 hours ago, Mopar1973Man said:

 

Make sure the shop is testing for AC ripple noise. Most shops just check for DC volts and DC AMps as long as it meets the requirement its passing. Now with today's electronics in the vehicle the DC power has to be clean and AC noise free. Lot of stores haven't upgraded test stands. 0.22 is a FAIL and very very damaging. A new or properly working alternator is typically 0.02 to 0.03 AC volts (or 20-30 mV AC).

So I tested ground to alt and got .30 and them ground and positive and got around .11 to .14. I took the bd noise isolator off and took it down the road and the tourqe converter kept locking up. So I'm at another dead end 

[Mopar1973Man]

1 hour ago, Kevynmurray18 said:

So I tested ground to alt and got .30 and them ground and positive and got around .11 to .14. I took the bd noise isolator off and took it down the road and the tourqe converter kept locking up. So I'm at another dead end 

 

Still a failing alternator... 0.11 to 0.14 is still too high... 

[Kevynmurray18]

1 hour ago, Mopar1973Man said:

 

Still a failing alternator... 0.11 to 0.14 is still too high... 

 

1 hour ago, Mopar1973Man said:

 

Still a failing alternator... 0.11 to 0.14 is still too high... 

Having orileys order the alt now. Will touch bases when I have the new one in. Any other tips while I'm waiting? Like things I should do that may help the dead pedal issue. 

[jlongjohn]

While waiting, check all grounds, clean and reconnect. Don’t forget the gray plastic connectors on the large grounds by the passenger battery. Use dielectric grease. My worst offenders were the ground strap from the pcm to the firewall and the main battery ground to the engine block. Then test AC noise again, ensure all electronics are off, including radio and hvac blower. Then turn one thing on and then off at a time, never two things at once. Check the AC noise each time and see if something causes your noise to increase. 

[Mopar1973Man]

10 hours ago, jlongjohn said:

My worst offenders were the ground strap from the pcm to the firewall

 

Remember that strap is not actually a circuit ground strap but noise ground. There is no connection from the case to the circuits inside.

 

10 hours ago, jlongjohn said:

Don’t forget the gray plastic connectors on the large grounds by the passenger battery.

 

Make sure to cycle the connection 3-4 times to clean the connector up with the grease.