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Discussion Starter · #1 ·
wondering about checking or replacing my PCM from my 2002 3500 van w/5.9l.

I believe my PCM is not working -getting a no start/no run - cut off when I was driving & has not started since them (was working fine before this happened)

I have replaced: cam position senor, crank position sensor, ignition coil, & ASD relay

I checked ALL fuses (in power dist. center & in fuse block inside vehicle) , fuel pump is working & there is power going to the coil, cam sensor, & crank sensor but no spark.

Is there a way to check to see if the PCM is bad? only check engine code is p1492-not sure what that is

Also if the PCM is bad are the PCMs interchangeable from yr to yr (ex 2003 w/5.2l or another yr w/5.2l or 5.9l) & if so what needs to be done to make it work on my vehicle? I was told that you need have have the VIN & mileage for it to work correctly.

I have only had the van for about 1 month & there is a sticker on the PCM that is was changed/and or reprogrammed 20k miles/ 3 yrs ago


Thanks in advance for any & all help!
 

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Discussion Starter · #4 ·
there has never been a 'no bus' message on the odometer-for as long as I've had it
as for the sticker on the PCM it looks as if somebody reflashed it or got a reflashed PCM & installed it.
just trying to figure out why it would stop running while driving down the expressway & then not start-while getting power @ the sensors & relays (coil has power but no spark-like it is not getting the signal to send spark to dist.
thanks for the help if there is anything else that might be a cause for this please let me know as I'm running out of options
I will see about getting a good scan tool to try & figure this put
 

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Discussion Starter · #7 ·
I have new info

I checked with a scan tool & wasn't able to get any info about/from the PCM

I have removed the PCM from the vehicle & removed the cover from the PCM to find a spot just above the far right connector that appears to be a burnt spot (smells burnt & looks like it is 'oozing' & sticky)

Not sure how to attach a pic of the problem (if there is a way please let me know-thanks)

Please let me know what anybody thinks so I can possibly fix the problem
 

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Discussion Starter · #8 ·
how & what do I need to do to check the 5 volt supply circuit?

I have checked the crank position sensor connections & there is 5 volts there & the cam position sensor connections there is 5 volts there & I checked the coil connections & there is 10.2 volts when cranked on one side of the connection & 2.3 volts on the other side of the connection (these are steady readings-they don't change during cranking)

thanks again for the help
 

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Discussion Starter · #10 ·
I was thinking that it might be that after checking the PCM and smelling a burnt wire smell in that area

I took the PCM out & turned the ignition key to on & then I got the 'no bus' in the odometer (normal -correct?) after reconnecting the PCM I got the odometer reading back

if any of this sounds wrong/incorrect please let me know

Thanks again for all the help!!
 

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Discussion Starter · #12 ·
Have new info-
I removed pcm from vehicle & sent to have repaired/rebuilt/reflashed (cost $139 + shipping) after getting back (about 10 days later) I installed the rebuilt/repaired PCM into the vehicle, making sure to remove the neg cable from the batt first, next I proceeded to try & start the van-when I tried starting the van it cranked but no start (I decided to recheck that I had all connections reconnected to the sensors as it had been wks since the start of the problem), all connections were connected, I tried cranking the van over again & noticed a burnt wire smell & noticed some smoke. I stopped the cranking & went to check where smoke was coming from (I had engine cover off inside of van & it looked like it was coming from front of vehicle) when I got to the front of the vehicle I noticed it was coming from the PCM right above the far drivers side connection (where I had noticed the burnt smell & saw the gel bubbled originally when I took the cover off the PCM before sending the PCM in for the rebuild)!
I'm still confused as to why/how this would happen?
I didn't experience this when it stopped running driving down the freeway as it took me several mins before I could look under the hood & by then if it was smoking it had stopped & whenever I have tried doing an diagnostics it has never done this.
If anyone has any ideas as to why or how this happened please let me know
I will talk to the company that rebuilt/repaired the PCM to see if they could explain it
PCM does have a lifetime warranty but I don't think it covers a fried PCM & I don't want & can't afford to buy a new PCM & have the same thing happen.

Thanks again for any & all help
 

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Discussion Starter · #14 ·
there hasn't been any wiring mods or repairs since I've had the van.
it was running fine right up to the time it cutout on the expressway-that is why it is confusing me (it acts like there is a short to ground or wires are shorting to each other to cause an excess voltage situation, but it hasn't caused a fuse to blow)
I will check the pin connectors & report the findings
it there a good place online that I can get the wiring diagrams?
thanks again for the help!
 

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Discussion Starter · #17 ·
is it possible to use a PCM from another van (different yr-2000) as a 'tester' just to see if it will start or to see if I get that same smoking problem?
Will/should van start but get a 'code' stored if the PCM is from another vehicle?
Don't want to buy a new PCM & have the PCM fry out if there is a wiring issue that caused the original PCM to smoke.
Thanks for any help
 
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