Hey Guys,
First time posting here...
I have a problem with a 1998 Neon SOHC. I replaced the water pump, put the timing belt on (it’s timed right) started the car…it ran for 5 mins then died. I checked the key dance code (54), replaced the cam shaft sensor with a BWD brand. Car has fuel pressure but no spark. So here what I have done so far:
· Replaced the Cam Sensor
· Checked Both Cam and Crank for the proper voltage (sensor to PCM) I am getting between .05v – 5v
·
Replaced 2 PCM’s from a ATX (I have a MTX) not sure if this matters but there was a youtube video showing a car being started with a ATX PCM in a MTX.
· Checked grounds (also checked the 4 or 5 grounds on the wire bundle to the PCM) there is continuity and Zero ohms.
· I rechecked the timing belt, it’s in time.
· Replaced the ASD (I feel it click on when cranking)

So here is where it gets tricky, the center wire plug to the coil pack has voltage when cranking. The two outside wires (pin 1 and pin 3) do not have voltage except when plugged into the coil pack and cranking. When cranking the two outside wires (pin 1&3) have voltage. I plugged a current tester into the back side of the plug but it does not send a ground signal. By the way, am using one of those current testers that test positive and negative (so it’s red when voltage is going through but doesn’t turn green to signal that ground is being sent) . It’s my understanding that the PCM send ground to the coil pack and somehow that creates the spark and this isn’t happening.
Is there something that I am missing here, do I need to order a refurbished PCM loaded to my VIN

 

The VIN needs to be entered in with a DRBIII.

 

OK, do you know if I can bring just the PCM to Dodge, or would they need the car?

 

They need the car.

 

why didn't you change crank sensor?

 

Becuase it I think it works. I assume if it didn't I wouldn't be getting the 12v to the coil pack.

 

Just so i understand, why do they need to program the VIN into the PCM? I don't think the 98's have the key transponder system.

 

you're thinking is flawed. 12v to the coil pack comes from the ASD relay. the crank sensor tells the PCM the postition of the crank shaft. the PCM then decides when to fire the ignition coil base on that sensor information. no info, no fire. huh, maybe you should have tossed in a crank sensor. BTW you often get a cam sensor code when you have a bad crank sender. cuz the pcm doesn't know which one is the good signal so it says out of sync code which points to cam usually

 

Yes, but it is my understanding that if the crank sensor is bad that the voltage won't change from .05v-5v on sensor wire to the PCM. When rotating the crank by hand with the ignition on the voltage measures 5v to .05v which is normal per the FSM.

Maybe I’m missing something here. I just it wouldn’t hurt to just by another sensor.

 

if you used an oscilloscope you would see if the sensor is working properly. a dvom is not accurate to read crank sensor signal.

the crank sensor sends a signal to the pcm, this signal determines when the pcm fires the coil. you said you have no spark and didn't replace the crank sensor. heck if the cam sensor is bad, you still have spark but no fuel.