Help! My daughters neon died and woun't start

Dragbear · Post by **Dragbear** » Sat Dec 04, 2010 8:11 am

I have been working on this car for 3 days with no luck.
It quit 3 times but would start back up after it sat for a while and run normal for a few miles then shut off again. Now it woun't start at all.

There are no engine codes
It has 60psi fuel pressure
No spark
Switched 12v on all fuses in the inside fuse box
Bat 12v on all relays and fuses in the under hood box
cleaned all grounds

I bought a book but there are no wireing diagrams of the engine or pcm and no information on how it all works.

Please help, Rick

Blivitt02 · Post by **Blivitt02** » Sat Dec 04, 2010 8:34 am

Where are you in NY, Rick?

I'd pull the timing cover off and inspect the timing belt, check the ASD for function, see where your spark is stopping, aka check wires, then coil pack, then signal and 12v to coil pack then the computer end of the harness

Dragbear · Post by **Dragbear** » Sat Dec 04, 2010 9:05 am

I am in north east Ney York state 3 hours from Montreal.

How do you check the ASD?
With the key on there is no power to the injectors or coil. On the GM cars there is 12v to everything and the pcm controls the ground. I don't know if this is true for the Dodge.

I don't belive there is any issues with the belt or engine because when it does start it runs normal. When it quits it is like shutting off the key.

Rick

Post by **occasional demons** » Sat Dec 04, 2010 9:37 am

If the ASD relay (coil) the PDC is not being energized, there will not be spark/fuel. If the contacts are going, it can cut the spark fuel at anytime. You could try switching the relays around to see if it fixes it. Usually ppl swap the horn relay with w/e suspected relay. You know the FP relay is good, because you have fuel pressure.
Check all the grounds under the hood also. If the PCM is losing ground, it will kill the engine.

PDC = underhood fuse/relay box Power Distribution Center

You should have power at the center wire of the ign. coil if the ASD relay is functioning. The two outer wires are grounded/opened via the PCM to fire the two coils. The common wire to the injectors should also have 12 volts. the individual colors are grounded via the PCM to fire them.

Dragbear · Post by **Dragbear** » Sat Dec 04, 2010 10:32 am

Thanks
If I am understanding you correctly there will be 12v on the center wire of the coil any time the key is on?
I am showing 0v. I did swap the relay with the one directly above with no luck.
I thought I read in another post that the pcm had to see a signal from the crank sensor before activating the ADS relay. Thats why I asked if there is 12v all the time with the key on.

I did find 12v on the TPS with the key on.
I tried hooking up a jumper wire from the bat to the center wire on the coil. It supplied 12v to all of the injectors allso but I still could not get the car to start.

Rick

Post by **occasional demons** » Sat Dec 04, 2010 1:58 pm

Yeah, you would prolly only see voltage on the center wire while cranking/running.

Just because you jumped power to the injectors/coil doesn't mean the PCM is going to ground them.

But it would tell me to start looking into the grounds. Even freshen up the PCM mounting screws.

Not that it is a big influence, but what year/transmission is her car? Might help for future issues.

Since this happens randomly, and no codes, I doubt it is a SKIM or sensor issue. A bad relay will set a code depending if it is the relay coil or contacts that are bad. The coil will give a code for that relay's circuit. The contacts will not set a code.

Clean all your grounds, and see what happens. The PCM specifically grounds at the driver side headlamp ground on the tie bar (upper radiator core support), above the headlight.

You should be able to check the coil/PCM circuit by putting a test light between either outer wire, and the center wire. It should flash while cranking, for either outer wire. This will tell you if the ground is good, and/or the PCM coil driver is working.

Edit: There should only be 5 volts at the TPS between the brown/yellow, and the violet/white wires. The orange/dk blue wire is the variable signal to the PCM.

If there is 12 volts between the BR/YL and VT/WT wire, the PCM 5v power supply has shorted, and is sending full voltage. Possibly there is a work around with a separate 5v power supply if this is the case, but a new PCM would prolly be needed.

Dragbear · Post by **Dragbear** » Sun Dec 05, 2010 8:54 am

I worked on it for a while yesterday and have some new information.
I had some help this time so with the test light on the center wire of the coil I had him turn the key on and the test light showed voltage for about 2 seconds then went off. At the same time I could hear and feel the ASD cycle on then off. I also had voltage at each injector.
This time I had him crank the motor over and with the test light still probing the center wire of the coil the test light came back on. So I think that means that the PCM is getting a singnal from I think the crank sensor that the motor is turning over and reactivates the ASD putting power back to the coil and injectors. But I still have no spark at the plugs and after cranking the motor over several minutes and pulling a sparkplug they are compleatly dry.
Next I pulled the coil and checked it for reristance on the primary and secondary windings and across the plug wire post. They all matched the numbers in the book. I reinstalled and tried to start the car with no luck.
The book says the only thing else it could be is the crank sensor, cam sensor, or PCM. I have a hard time beliving it is a sensor with no engine codes because when the crank sensor went last year it gave a code. I would clear the code and as soon as I started cranking the motor over it would set the code again.
Next I pulled the PCM cleaned the mounts and wire grounds, checked the wiring and reinstalled it. I dont belive it uses the mounts as a ground but I cleaned them. I also pulled the crank sensor to check for a damaged sensor and wires and reinstalled.
Got it all back together hit the key and it STARTED!! I thought it must of been the ground on the PCM. We drove it around the block and it ran very well so we let it sit there to warm up and I went in the house for a minute came back out and it had quit and would not start.
It is still doing the same thing it would start run for a few minutes and quit. Let it set for a while and it would start.

Sorry for being long winded but realy need to get this thing running.

Thanks, Rick

Post by **occasional demons** » Sun Dec 05, 2010 1:32 pm

What year is it?

It seems something is either heating up, building enough resistance to kill a circuit. It could be an internal PCM issue. I have no ideas left.

If it is pre '03, you may not have SKIM, (black key, gray key is SKIM) and if you could get/borrow another non SKIM pcm, it could be swapped to see if that cures it.

With SKIM, the VIN would need to be flashed at a dealer, and really not worth it for backyard diagnostics.

Dragbear · Post by **Dragbear** » Sun Dec 05, 2010 3:19 pm

It is pre 2003. It is 2001
Yea we thought the same in just swapping in another pcm
We will check.the junk yards this week.
I wish I had the dealership troubleshooting flow charts for this issue . We just don't have the money to spend on trial and error. The book I have is not much on trouble shooting .

Thanks for the help, I will let you know how the pcm works out .
Rick