No start. PCM dead?

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Gnuserup
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Post by Gnuserup » Tue Apr 19, 2011 3:09 pm

it´s just the hope that either one of the included programs will get a connection or the two interfaces work differently to contact the PCM, don´t know.

Do you have ABS or cruise control ?

I think about, which functions communicate with the pcm.

Just tried on my 2000 - if I turn the ignition on without cranking, after a few seconds I could activate the cruise control and the display shows. By doing that I hear a little ticking sound, a relay or something, Maybe that won´t work without a working PCM and/ or a working bus.

Related to the SKIM-discussion I think, if youcan´t get a contact neither with your OBD-Adaptor nor by the keydance, a SKIM malfunction must not be the cause, as you remember a connection to the PCM should function even without a key (valid or not).

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Post by OB » Tue Apr 19, 2011 3:55 pm

supercommuter wrote:Not sure if I mentioned this before, but when replacing the manifold, I broke off the little black box on the back of the head, just below the valve cover. I figured it was a ground wire, and the black box was just a fancy wire terminal, so I chucked it and connected that wire directly to the bolt on the back of the head. Apparently that was a "noise suppressor"?

I'm wondering if I could have damaged something by connecting that wire directly to ground?
Not related, the noise suppressor is part of the ground circuit for the ignition coil. I imagine the black box contains a resistor grid of some sort that helps lower RFI in the electrical system.

There are specific pinout tests that can be performed to test the PCM, detailed in the service manual. I would recommend these before throwing parts at it.
-Derek

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Gnuserup
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Post by Gnuserup » Tue Apr 19, 2011 4:39 pm

Don´t know if this has to say anything, but it costs nothing to try...

What´s about the cluster test procedure ?

viewtopic.php?t=54241&highlight=cluster+test

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Post by supercommuter » Thu Apr 21, 2011 9:34 am

Sooooo... as it turned out, the PCM was fine. Everything is cool now. That's all I'm gonna say. :roll:
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Post by Danteneon » Thu Apr 21, 2011 9:37 am

It was something simple wasn't it?
If I could just figure out how to meld the Outback and the Neon into one car...

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Post by Gnuserup » Sat Apr 23, 2011 9:06 am

Would be really great to hear what had caused your trouble - please let us know :tongue8:

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Post by supercommuter » Sat Apr 23, 2011 12:42 pm

Gnuserup wrote:Would be really great to hear what had caused your trouble - please let us know :tongue8:
Alright, it was a fuse. And I could have sworn I checked all the fuses two and three times! I know I did! Anyway, when I grounded the wire off the noise supressor, I must have blown the ASD fuse. I swear I friggin checked that fuse!

So I did find a new noise suppressor in a junkyard for $5.

I'm an idiot, in my haste just to get everything back together I just assumed that wire was supposed to be grounded.

So once the fuse was replaced, everything worked fine. No codes and it starts right up. I know, I'm an idiot. :roll:
Last edited by supercommuter on Sat Apr 23, 2011 12:53 pm, edited 1 time in total.
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Post by Danteneon » Sat Apr 23, 2011 12:49 pm

Eh, live and learn. Sometimes easy problems that are turned into major issues are the ones we learn the most from :thumbup:
If I could just figure out how to meld the Outback and the Neon into one car...

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Post by Gnuserup » Sat Apr 23, 2011 2:18 pm

Never mind - I am glad that the reason was such a cheap thing :D

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Post by occasional demons » Sat Apr 23, 2011 11:18 pm

See, if you had manually connected the ASD contacts, it may have ran. :lol:


Anyways, as the the PCM swap questions: Yes Derek, non NGC you can swap non SKIM PCM's without flashing the VIN. My car is more than proof, especially since it is a SKIM pcm, and my car is not. I am just damn lucky on the SKIM part.

supercommuter, it matters mainly as to what transmission on '02 models. Since they use the 41te ATX. The TCM needs to communicate with the PCM in that case. The '01 and '02 MTX pcm will work with the '01 ATX, but the TC solenoid will not work to lock up the TC clutch. The '01 ATX pcm will run the '01/'02 MTX cars, but there will be a CEL for the TC lock up solenoid not being there. A resistor may cure this. There is also the issue of making it think it is in gear, or it will be rev limited to 3000 rpm, or something close to that. The in gear rev limit is also 6000 rpm, vs 6750 on MTX's.

So yes, it is preferable to get one with the same transaxle, but not 100% necessary if you can "rig" it up to your needs.
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Post by NickKo » Sun Apr 24, 2011 11:59 am

supercommuter wrote:
Gnuserup wrote:Would be really great to hear what had caused your trouble - please let us know :tongue8:
Alright, it was a fuse. And I could have sworn I checked all the fuses two and three times! I know I did! Anyway, when I grounded the wire off the noise supressor, I must have blown the ASD fuse. I swear I friggin checked that fuse!

So I did find a new noise suppressor in a junkyard for $5.

I'm an idiot, in my haste just to get everything back together I just assumed that wire was supposed to be grounded.

So once the fuse was replaced, everything worked fine. No codes and it starts right up. I know, I'm an idiot. :roll:
No, you are NOT an idiot. :)

Most of all, THANK you, for coming back and letting us know what the issue is.
This will come in handy, to educate others who may end up having the same issue.


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Post by neonpla » Wed May 11, 2011 4:44 pm

Ok so I have the same problem, I was driving home my 01 last night it was raining. Out of no where it turned off and I coasted to the side of the road, I have full power in the car and all accessories work. I don't hear the fuel pump come on, starter does not turn or click, I disconnected the fuel line at the rail to see if it was coming out and no fuel at all.

Battery is good, should I check the asd? if so how can I test it.
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Post by neonpla » Wed May 11, 2011 10:02 pm

Fixed, it was the fp/asd fuse
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Post by 00Neon RCR » Thu Jun 16, 2011 12:28 am

neonpla wrote:Fixed, it was the fp/asd fuse
I'm having this problem. However, when you say FP/ASD fuse... do you actually mean the relay?

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Post by NickKo » Sun Jun 19, 2011 9:21 am

00Neon RCR wrote:
neonpla wrote:Fixed, it was the fp/asd fuse
I'm having this problem. However, when you say FP/ASD fuse... do you actually mean the relay?
I *think* he is referring to the actual fuse itself, not the relay.....

Free bump for you.


- Nick
-1998 2-dr SOHC MTX= 57mm TB; Maddog STS
-2000 Ply.LX w/MTX = Maddog STS; CAI; 2.5 exh.; 60mm T/B
-2001 ATX w/Syked PCM + Magnum header
-2001 ACR w/SRT T/B bored out to 55mm

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Post by OhNoA2.0 » Thu Jun 30, 2011 12:30 am

supercommuter wrote:
Gnuserup wrote:Would be really great to hear what had caused your trouble - please let us know :tongue8:
Alright, it was a fuse. And I could have sworn I checked all the fuses two and three times! I know I did! Anyway, when I grounded the wire off the noise supressor, I must have blown the ASD fuse. I swear I friggin checked that fuse!

So I did find a new noise suppressor in a junkyard for $5.

I'm an idiot, in my haste just to get everything back together I just assumed that wire was supposed to be grounded.

So once the fuse was replaced, everything worked fine. No codes and it starts right up. I know, I'm an idiot. :roll:
I'm having a similar issue, what fuse was it exactly? And what is a "noise suppressor"?
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Post by Gnuserup » Thu Jun 30, 2011 11:47 am

maybe that piece which kills the electrical influence to the radio (damn - what´s his name ... ?)

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Post by OB » Thu Jun 30, 2011 9:48 pm

OB wrote:
...the noise suppressor is part of the ground circuit for the ignition coil. It helps lower RFI in from the ignition system.
-Derek

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Post by occasional demons » Fri Jul 01, 2011 12:14 am

On the 2.0's the noise suppressor is the small black square capacitor that is mounted on the head, backside, CPS end.

It has the common power for the injectors, and IIRC the coil plugged into it. In addition to preventing radio noise, it keeps the peaks out of the power from the injectors, and coil firing. Sort of like the pulsation damper in the fuel line/fuel rail. Never bypass it, and connect that wire directly to ground.

The FP/ASD fuse should be marked on the PDC cover.

Edit: Fuse 21

I have had the actual ASD relay fail while running, too. Luckily swapping it with another relay got me back on my way.
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Still on the fuze problem

Post by dadmoonbunny » Fri Jul 22, 2011 12:18 am

How about an occasional problem with the ASD fuse "blowing"?

I have replaced the PCM, All sensors except the O2 and battery blanket sensors. All relays have been replaced as well..

I have been through the wiring harness under the hood, and redid all the ground terminals to bare metal and sealed them. I have replaced ALL relays and fuses in the "power center"under the hood. I upgraded the battery cables to a larger diameter cable on both positive and negative sides as well. ALL connections are tight.

I still have a problem with the ASD fuse "blowing".

So, two questions:

1. What could be the cause?

2. What systems/components/circuits are involved with the ASD fuse and relay?

ANY constructive help/info is appreciated.[/u]

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part number request

Post by dadmoonbunny » Sun Jul 24, 2011 1:17 pm

anyone have a part number for the "noise suppressor"?

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Post by occasional demons » Sun Jul 24, 2011 9:41 pm

If you suspect the capacitor is shorting to ground/getting there, just unplug it. If the fuse doesn't blow anymore, you found the problem. That cap is connected to the positive feed for the coil(s) and injectors.
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UPDATE ON TEH NOISE SUPRESSOR

Post by dadmoonbunny » Fri Jul 29, 2011 4:02 am

As of this last Wednesday, There are only four of them left at dealerships in the US according to computer records. One in Louisiana. one in Texas, one in Kansas and one in South Dakota.

I stopped in a Dodge dealership on the way home from a job and had them run a search. They told me it was about 20.00 USD not including S&H for each one.

Does anyone know the (electronic ) values on that capacitor/resistor/diode?

I believe that, if we knew the value, we could go find one at the electronic store, and wire it into the harness. Only two leads. One would be ground, one would connect to the wire to the harness.

C'mon folks, for smart people like us, that should be childs play. As well, I am sure that you could could (maybe) pick up two or three for the price of the dealership charges for one. If you're worried about that fancy black case, incase the replacement in some sort of resin, or perhaps polyurethane.

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Re: Still on the fuze problem

Post by dadmoonbunny » Tue Aug 02, 2011 12:30 am

dadmoonbunny wrote:How about an occasional problem with the ASD fuse "blowing"?

I have replaced the PCM, All sensors except the O2 and battery blanket sensors. All relays have been replaced as well..

I have been through the wiring harness under the hood, and redid all the ground terminals to bare metal and sealed them. I have replaced ALL relays and fuses in the "power center"under the hood. I upgraded the battery cables to a larger diameter cable on both positive and negative sides as well. ALL connections are tight.

I still have a problem with the ASD fuse "blowing".

So, two questions:

1. What could be the cause?

2. What systems/components/circuits are involved with the ASD fuse and relay?

ANY constructive help/info is appreciated.[/u]
So,

After having dollied the car over five hours of highway back to my place, We no longer trust this car. I thought we had it great. Replaced the battery before the trip, and the car functioned without any problem until we were on the return leg. Then it started popping that durned FP/ASD fuse again. Now, We have it sitting in the yard. If we want to move it, it's either drag it, push it, or have a CASE of the fuses for it.

From what I have read on this thread, this is a well known problem with this car. The dealerships cannot solve it, I tried three separate ones, at well over 700.00. I have almost run out of patience with this car.

Look, can someone PLEASE do a step by step to figure out what is wrong? That way we can sticky this problem and get the word out.

I am hesitant to upgrade to aviation technology with this thing.

Replacing fuses with pop out/resettable breakers will be expensive and VERY time consuming. Not counting figuring out where to put the breaker panel once completed.

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Post by dadmoonbunny » Tue Aug 02, 2011 10:39 am

Note that this fuse feeds not only the fuel pump relay output circuit, but also the autoshutdown (ASD) relay output... and ASD goes all over the underhood area.

The most common source of shorting to ground occurs at the noise suppressor . It's nothing more than a solid state capacitor with a single wire attached and is located on the back side of the cylinder head near the point where your harness drops down to the back side of the engine (yet another possibility). The capacitor itself seldom shorts but the short pigtail that connects it to the harness does. Inspect the area for bare copper showing and be extra careful of any point where wiring actually touches a metal surface like the valve cover or the corner of the cylinder head.

As hinted, the section of harness that travels along the back-upper part of the cylinder head has its problems once it arrives in the oil and heat-rich zone behind the engine. Either one are hard on wiring, but when combined... it's like 4X worse. Oil softens individual wire insulation and the heat will pretty much meld the whole mess together. When the ASD positive voltage source meets a ground within the wire, you've got problems. Peel this section of harness apart in the affected area until the problem is found or you have nothing but clean undamaged wiring from some point on.

While I don't know if it will apply to this particular shorting problem, Neons have historically had poor luck when they tangle with parking blocks or something of that nature. The lower radiator support can be pushed backward considerably, which can pinch wiring between the support and the automatic transmission. If you look down on the driver's side of the engine compartment and see less than an inch of daylight showing between the trans and support, this would be a good place to investigate. One leg of the red/ white wire that does NOT pass through the ASD relay, yet is from the same fuse circuit, travels to the PCM (engine controller) which is mounted directly to the inner surface of the radiator support and will have wiring that could be involved.

If tested with a meter or test light, the circuit will always show continuity to ground even when healthy thanks to it being used to power the oxygen sensor heaters (2). To isolate the circuit, both sensors would have to be disconnected... which means jacking the car up. Let's take a hard look underhood first to see if the two or three more likely shorting points can be located and we'll push on from there.


I don't know who originally wrote this, as I found it during a web search. All credit goes to the author, whomever they may be. I am not trying to violate any rules, but figured this was a need - to - know item. Any Idea how I can attach the wiring diagram that goes with this write-up?

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Post by occasional demons » Tue Aug 02, 2011 12:06 pm

Where did you find it? Should just post a link to the article.
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Re: UPDATE ON TEH NOISE SUPRESSOR

Post by dadmoonbunny » Fri Aug 05, 2011 11:44 pm

dadmoonbunny wrote:As of this last Wednesday, There are only four of them left at dealerships in the US according to computer records. One in Louisiana. one in Texas, one in Kansas and one in South Dakota.

I stopped in a Dodge dealership on the way home from a job and had them run a search. They told me it was about 20.00 USD not including S&H for each one.

Does anyone know the (electronic ) values on that capacitor/resistor/diode?

I believe that, if we knew the value, we could go find one at the electronic store, and wire it into the harness. Only two leads. One would be ground, one would connect to the wire to the harness.

C'mon folks, for smart people like us, that should be childs play. As well, I am sure that you could could (maybe) pick up two or three for the price of the dealership charges for one. If you're worried about that fancy black case, incase the replacement in some sort of resin, or perhaps polyurethane.
Okay, After A LOT of research, I have located the part and dechiphered the numbers on it. Turns out that that "little black box" contains a .47 microfarad capacitor. They are used on Dodges, Hondas, Isuzus, and LORD knows how many others around the world. Several other boards such as dodge turbo truck boards also have complaints about this thing KILLING ignition systems.

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Re: UPDATE ON TEH NOISE SUPRESSOR

Post by dadmoonbunny » Mon Aug 08, 2011 11:08 pm

dadmoonbunny wrote:As of this last Wednesday, There are only four of them left at dealerships in the US according to computer records. One in Louisiana. one in Texas, one in Kansas and one in South Dakota.

I stopped in a Dodge dealership on the way home from a job and had them run a search. They told me it was about 20.00 USD not including S&H for each one.

Does anyone know the (electronic ) values on that capacitor/resistor/diode?

I believe that, if we knew the value, we could go find one at the electronic store, and wire it into the harness. Only two leads. One would be ground, one would connect to the wire to the harness.

C'mon folks, for smart people like us, that should be childs play. As well, I am sure that you could could (maybe) pick up two or three for the price of the dealership charges for one. If you're worried about that fancy black case, incase the replacement in some sort of resin, or perhaps polyurethane.
Stopped off at a junk yard, and they GAVE me the capacitor. I cleaned up the metal mounting tab, and the electrical contact. I installed it, but DID NOT connect it. Car fires up and runs nicely. Road test SOON!

( Bumpy dirt and gravel road, and some pavement, at either speed limit or safest possible maximum speed. Gonna shake this thing up and try to get it to fail!) More to come!!
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Post by Boyscoutgonebad » Tue Jan 28, 2014 10:00 am

Gnuserup wrote:
Related to the SKIM-discussion I think, if youcan´t get a contact neither with your OBD-Adaptor nor by the keydance, a SKIM malfunction must not be the cause, as you remember a connection to the PCM should function even without a key (valid or not).
Can Anyone verify this? Can a SKIM issue cause the PCM not to read?
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Post by sidepipe87 » Tue Jan 28, 2014 1:20 pm

Not to read what? codes from a key dance? codes on a reader? What are you trying to do? If the car won't start and nothing is activating, try checking the ASD fuse first.
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