Electrical noise causing ECM to force up/down shifting
#1
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Location: tehachapi CA
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Electrical noise causing ECM to force up/down shifting
I had a problem that Dodge had diagnosed as a TPPS. After getting the sticker shock on the cost of a new one, I located one on e-Bay and installed it. Many of the people on this site had experienced simular problems, and the advice I got ranged from cleaning battery cables to new wire harnesses to isolate the TPPS signal from everything else.
My "new TPPS" which I got off e-Bay started doing the same thing after about 3500 miles or so. I then purchased a isolation wire harness (which I was told may or may not work) worked for another 2500 miles then the problem returned!.
I got frustrated and decided never to buy another dodge. I turned the radio up, and began to notice that everytime i went over rough pavement, or hit a pot hole, my radio "crackled" as if there was lightning striking nearby. The transmission also did it's "up/down shift.
I pondered this for awhile, and wondered if there was s loose ground cable somewhere and began my search. After locating several of these little braided wire ground cables, I removed them, and cleaned every contact point. I re-installed them, but the problem was still there!
Then I hit on it! Alternator brushes had become so worn the springs could not provide enough tension to keep the brushes in full contact with the communtator. Replaced brushes, and so far problem has not returned.
My "new TPPS" which I got off e-Bay started doing the same thing after about 3500 miles or so. I then purchased a isolation wire harness (which I was told may or may not work) worked for another 2500 miles then the problem returned!.
I got frustrated and decided never to buy another dodge. I turned the radio up, and began to notice that everytime i went over rough pavement, or hit a pot hole, my radio "crackled" as if there was lightning striking nearby. The transmission also did it's "up/down shift.
I pondered this for awhile, and wondered if there was s loose ground cable somewhere and began my search. After locating several of these little braided wire ground cables, I removed them, and cleaned every contact point. I re-installed them, but the problem was still there!
Then I hit on it! Alternator brushes had become so worn the springs could not provide enough tension to keep the brushes in full contact with the communtator. Replaced brushes, and so far problem has not returned.
#3
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bad alternator ????
I have been having this problem since new have wasted over $15,000.00 and have been told that I have to get used to it. This peice of junk has cured me from ever buying Cryslurrsss cumminsssssss junk ever again. ( Go Cat Power) I have seen the output on an oscilloscope and it was good just like in trade school the o/p of wave forms for generators. The problem seems to be comming from the PDC If someone can look at them I would be ever so extremely grateful. For I wait for the day that I could actually say that it was good to drive.Replacing the Alternator didn't fix the problem and oh yes measured the capicitance it was 15 MFD. good or bad anyone???????
There is an arc in the voltage that comes out of the PDC and it is in everything so fueling is bad. Is there a capacitor size that might smooth this out.???????? For I have another 12 plus hours of suffering driving tomorrow
There is an arc in the voltage that comes out of the PDC and it is in everything so fueling is bad. Is there a capacitor size that might smooth this out.???????? For I have another 12 plus hours of suffering driving tomorrow
#6
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From what I read at the TDR, the fix is a noise filter that goes on the APPS and it costs $37.00 from Diesel Transmission Technology (1-866-504-4002). I just happened to order one and will have it in ASAP. The guy there said it must be soldered in place and reset the APPS ONLY the way they tell you in THEIR instuctions. Ill post what happens.
#7
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Noisy ALT.
Well I have had this (noise) since new and changing the alt didn't help at all. Which is very confusing! Also changed the batteries so between this it should have helped. Have had to suffer with this junk the last 3 plus days and to me it seems that the fuel shut off shuts off the engine twice every cycle. I hate being passed by loaded semis!!! It is back to the rev and scream engine. NOOOOOO power.
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#8
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Location: Aurora, Ontario
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I had problems with mine to hunting for lockup in the sping. I just got one of DTT's Noise boxes and that totally cured my problem. My truck shifts rock solid now. Anyways just sharing my experience and well mine was an easy fix.
#9
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Electrical System Arc
I have an arc in the system maybe from the PDC Juntion 1 or 2 and so far can't find anyone who knows what I am talking about . Why do I have the one in North Americia that is NO GOOD FROM NEW???????? This is tooooo expensive to keep throwing money at it having re&re boys playing!!!!! I should have been able to just enjoy the truck, like most have been able to do!!!!! Before the expensive parts replacment starts.
#10
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neveragain: Does the voltage spike up or does it drop low? (measuring PDC to chassis or engine ground)
One point to try IMHO (I'm a cheapo) would be first to install a PCM ground wire to the batt neg passenger side. (simply from the PCM case)
Then I'd route a new cable from the alternator output to the PDC (take a good sized one) and replace the 140 amp fuse, check the post connectors on both sides of the fuse.
I know this might sound weird but that was what cured a friends truck, even though the cable from the alt to the PDC checked out good....
Just my 2c
AlpineRAM
One point to try IMHO (I'm a cheapo) would be first to install a PCM ground wire to the batt neg passenger side. (simply from the PCM case)
Then I'd route a new cable from the alternator output to the PDC (take a good sized one) and replace the 140 amp fuse, check the post connectors on both sides of the fuse.
I know this might sound weird but that was what cured a friends truck, even though the cable from the alt to the PDC checked out good....
Just my 2c
AlpineRAM
#11
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Electrical ARCing
Thank You AlpineRam much apperciated.
Lets see if I remember what you said,the 140 A fuse is good. Several months ago I cleaned and commoned up the grounds on the truck.( It sure made the head lights work better) Didn't help at all. As for the Alt o/p that might be a good one to start with. Sorry haven't got the osocilloscope readings on here yet but if you go to 2 ND-TIME readers rigs in TDR some of the scope readings are there. I am sure that it is causing the fuel shut off to turn off and on for it is a lot worse in the last year.
Lets see if I remember what you said,the 140 A fuse is good. Several months ago I cleaned and commoned up the grounds on the truck.( It sure made the head lights work better) Didn't help at all. As for the Alt o/p that might be a good one to start with. Sorry haven't got the osocilloscope readings on here yet but if you go to 2 ND-TIME readers rigs in TDR some of the scope readings are there. I am sure that it is causing the fuel shut off to turn off and on for it is a lot worse in the last year.
#13
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Originally Posted by Big Deezul
This is a common problem and I have seen this same thread pop up many times. Buy the noise filter for $35 and the problem is solved. It's very easy to install.
Where can I buy a filter?