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Discussion Starter · #1 ·
I have 2003 Dodge Caravan SE 2.4L. I had not driven it for about 3 weeks, because we recently bought another used vehicle. One day my wife went in the garage and the minivan was making a constant noise, but it went away. I tried to start the car, but the battery was completely dead. I grabbed my portable jump start device and the car was cranking and all of the sudden it did like of it did not have enough power. I decided to do it the old fashion way with jumper cables and this time the fuel pump would not come on. I then checked the fuses and the fuel pump fuse was blown. When I went to replace it with a new one..... it blew it immediately. I Google and someone said to remove the fuel pump relay to remove the Pump from the equation. If the fuse did not blow then it was a bad fuel pump, but if the fuse blew it was not the fuel pump. I did that and the fuel pump fuse still blew with the fuel pump relay disconnected.

I decided to take the battery to Walmart to have it tested and it was a bad battery and got it replaced under warranty. I am trying to see whats going on and if jump starting the car with a bad battery could had damaged the PCM? I really hope is not the fuel pump....., because last time I changed it, it was a pain. I rather it be the PCM, since it would be cheaper to send it out to people on eBay who can repair it for $90.
I really doubt it is a grounding issue, since it was cranking at the beginning. Any advice would be greatly appreciated..... Could the PCM be blowing the fuse? I mean it blows immediately as I connect the negative cable back to the battery.

Update:

Disconnected the PCM completely, put a new 20AMP fuel pump fuse, and removed the fuel pump relay and put a pin connecting 87 & 30 to send power to the fuel pump and the fuel pump motor is working. I am leaning towards the PCM and not a grounding wire. Can anyone confirm this for me?
 

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I Google and someone said to remove the fuel pump relay to remove the Pump from the equation. If the fuse did not blow then it was a bad fuel pump, but if the fuse blew it was not the fuel pump.
That info is kinda right. I looked at an OE diagram and your fuse box is known as an Integrated Power Module. I'm sure you noticed that your fuel pump fuse and your fuel pump relay are both in the IPM. What that means, is if you pull the relay and the fuse still blows immediately, that leans heavily to the likelihood that there is a dead short in the IPM itself. That's a common problem for a lot of Mopar makes & models due to corrosion. It can be on the board inside the IPM and it could be spread throughout the wires that connect to it on the under side.

I find it interesting that the fuse doesn't blow with the PCM disconnected. That leaves me to believe that power on the board is shorted to the fuel pump relay control wire. The FP relay control wire is a ground circuit. It's not a guarantee, but it's a viable possibility. If I had your van in front of me, I'd plug the fuel pump relay back in and leave the PCM disconnected. If the fuse pops, pull the fuel pump relay back out and install the AC compressor relay in its place.(Or any accessory relay in the fuse block of the same size and pin count) Then throw another fuse in it. If the fuse doesn't pop, plug the PCM back in and see if the fuse pops now. If the fuse still pops after you plug the PCM back in, then you're probably looking for that short in the IPM. If the fuse no longer pops with everything plugged back in, the original fuel pump relay is probably shorted.

That's a great place to move forward with your diagnostics. It may not solve all your problems, but it should answer a lot questions.
 
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Discussion Starter · #3 ·
That info is kinda right. I looked at an OE diagram and your fuse box is known as an Integrated Power Module. I'm sure you noticed that your fuel pump fuse and your fuel pump relay are both in the IPM. What that means, is if you pull the relay and the fuse still blows immediately, that leans heavily to the likelihood that there is a dead short in the IPM itself. That's a common problem for a lot of Mopar makes & models due to corrosion. It can be on the board inside the IPM and it could be spread throughout the wires that connect to it on the under side.

I find it interesting that the fuse doesn't blow with the PCM disconnected. That leaves me to believe that power on the board is shorted to the fuel pump relay control wire. The FP relay control wire is a ground circuit. It's not a guarantee, but it's a viable possibility. If I had your van in front of me, I'd plug the fuel pump relay back in and leave the PCM disconnected. If the fuse pops, pull the fuel pump relay back out and install the AC compressor relay in its place.(Or any accessory relay in the fuse block of the same size and pin count) Then throw another fuse in it. If the fuse doesn't pop, plug the PCM back in and see if the fuse pops now. If the fuse still pops after you plug the PCM back in, then you're probably looking for that short in the IPM. If the fuse no longer pops with everything plugged back in, the original fuel pump relay is probably shorted.

That's a great place to move forward with your diagnostics. It may not solve all your problems, but it should answer a lot questions.
Thanks for replying back. You have given some guidance on what to try. I will see if I have sometime this weekend to troubleshoot the Minivan. Very much appreciate your input and as soon as find the cause I will post back here so anyone with the same problem, can find a solution. Thank you again.
 

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Discussion Starter · #4 · (Edited)
That info is kinda right. I looked at an OE diagram and your fuse box is known as an Integrated Power Module. I'm sure you noticed that your fuel pump fuse and your fuel pump relay are both in the IPM. What that means, is if you pull the relay and the fuse still blows immediately, that leans heavily to the likelihood that there is a dead short in the IPM itself. That's a common problem for a lot of Mopar makes & models due to corrosion. It can be on the board inside the IPM and it could be spread throughout the wires that connect to it on the under side.

I find it interesting that the fuse doesn't blow with the PCM disconnected. That leaves me to believe that power on the board is shorted to the fuel pump relay control wire. The FP relay control wire is a ground circuit. It's not a guarantee, but it's a viable possibility. If I had your van in front of me, I'd plug the fuel pump relay back in and leave the PCM disconnected. If the fuse pops, pull the fuel pump relay back out and install the AC compressor relay in its place.(Or any accessory relay in the fuse block of the same size and pin count) Then throw another fuse in it. If the fuse doesn't pop, plug the PCM back in and see if the fuse pops now. If the fuse still pops after you plug the PCM back in, then you're probably looking for that short in the IPM. If the fuse no longer pops with everything plugged back in, the original fuel pump relay is probably shorted.

That's a great place to move forward with your diagnostics. It may not solve all your problems, but it should answer a lot questions.
Different scenarios I tried:
  1. Everything connected without the PCM and I connect the negative to the battery the FP fuse doesn't blow.
  2. As soon as I connect the PCM and connect the negative to the battery the FP fuse blows.
  3. I tried connecting all the PCM connections except the one labeled C1 that has connection to the FP fuse and the fuse doesn't blow.
If it was the IPM, the fuse would blow without the PCM connected. Seeing that it only blows when the C1 PCM plug gets connected..... leads me to believe the PCM is BAD or the Orange Red wire coming from the PCM to the FP fuse is making ground somewhere else. But OR/RD wire is neatly bundled and I didn't see any rips or tears where the wire would be making ground. Also if that wire was making ground, even after disconnecting it from the PCM it would still blow and it doesn't... it only blows as soon as I connect the C1 to the PCM. I am not sure if the IPM is the problems,since it doesn't blow the fuse without the PCM connected. I don't think is a frayed wire, since it would have blown without the PCM connected.... If the wired is grounding between the PCM and the IPM. I added the diagrams to see if you can give me more advice. Thank you.

Someone else told me to connect a test light to the negative of the battery and put the prong end in the OR/RD wire on the C1 plug. Since the test light end was large, I inserted a small paperclip to make contact with the OR/RD wire and used a gator clip wire to connect the paperclip to the test light end. Then, I proceeded to connected the negative wire to the battery and the Fuel Pump fuse still blew.
 

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If it was the IPM, the fuse would blow without the PCM connected. Seeing that it only blows when the C1 PCM plug gets connected..... leads me to believe the PCM is BAD or the Orange Red wire coming from the PCM to the FP fuse is making ground somewhere else.
Based on what you're telling me; the way I'd move forward is to go to that OR/RD wire at the PCM C1 connector. Either depin it from C1 or cut that wire up about an inch and a half from the connector. (Give yourself room to make a clean repair to the wire after testing.) Then plug C1 back into the PCM. If the fuse still blows, you have a short and I'm strongly inclined to believe it's a wire to wire short it's in another one of the wires coming from C1, whether you can see it or not. If the fuse does not blow, then you've just about proved your PCM to have an internal short.

There is one more thing you can do to test the OR/RD wire for a short to ground. With C1 disconnected, also pull the fuse. This way the wire is totally isolated. Connect your test light to battery (+) and probe the open fuse cavity or OR/RDpin at C1. The test light should stay off. If it lights up, it's because there's a short in the wire. Another option is if you have a multimeter, set it to Ohms and clamp one lead on any clean ground under the hood and put the other lead on either end of the same wire. You should read infinite resistance or OL or whatever your meter's appropriate symbol shows. It's two ways to get to the same conclusion.

In any event that you can prove the short is before the PCM, there actually still is a chance that the IPM is shorted. Or at least the connectors that plug into the back of it could be shorted. Corrosion between two terminals could be acting as a bridge to a ground circuit that just so happens to not have any continuity until C1 at the PCM gets reconnected. You'd be amazed at what can happen with corrosion in a fuse block. If you get to the point you know it's a short in the wiring, at least disconnect C3 at the IPM and check it for fuzzy shit before you open up any of the wiring harness. C3 at the IPM has the other end of your OR/RD wire. The IPM has a couple lock tabs on the side opposite of the battery and then the IPM tilts up on a hinge. I can't remember for sure, but you may have to pull the battery to allow the IPM to fully tilt. WARNING *I forgot that my copy of the factory service manual is limited to 05-07 model years. C3 may not be the right connector for your 03, but do check IPM connectors just the same.

Just curious; did you ever pull the fuel pump relay at any time during your testing?
 
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Discussion Starter · #6 ·
Based on what you're telling me; the way I'd move forward is to go to that OR/RD wire at the PCM C1 connector. Either depin it from C1 or cut that wire up about an inch and a half from the connector. (Give yourself room to make a clean repair to the wire after testing.) Then plug C1 back into the PCM. If the fuse still blows, you have a short and I'm strongly inclined to believe it's a wire to wire short it's in another one of the wires coming from C1, whether you can see it or not. If the fuse does not blow, then you've just about proved your PCM to have an internal short.

There is one more thing you can do to test the OR/RD wire for a short to ground. With C1 disconnected, also pull the fuse. This way the wire is totally isolated. Connect your test light to battery (+) and probe the open fuse cavity or OR/RDpin at C1. The test light should stay off. If it lights up, it's because there's a short in the wire. Another option is if you have a multimeter, set it to Ohms and clamp one lead on any clean ground under the hood and put the other lead on either end of the same wire. You should read infinite resistance or OL or whatever your meter's appropriate symbol shows. It's two ways to get to the same conclusion.

In any event that you can prove the short is before the PCM, there actually still is a chance that the IPM is shorted. Or at least the connectors that plug into the back of it could be shorted. Corrosion between two terminals could be acting as a bridge to a ground circuit that just so happens to not have any continuity until C1 at the PCM gets reconnected. You'd be amazed at what can happen with corrosion in a fuse block. If you get to the point you know it's a short in the wiring, at least disconnect C3 at the IPM and check it for fuzzy shit before you open up any of the wiring harness. C3 at the IPM has the other end of your OR/RD wire. The IPM has a couple lock tabs on the side opposite of the battery and then the IPM tilts up on a hinge. I can't remember for sure, but you may have to pull the battery to allow the IPM to fully tilt. WARNING *I forgot that my copy of the factory service manual is limited to 05-07 model years. C3 may not be the right connector for your 03, but do check IPM connectors just the same.

Just curious; did you ever pull the fuel pump relay at any time during your testing?
No I did not remove the FP relay, since I had already proven there was not a short on the fuel pump side. If I remember correctly, I disconnected the PCM (because if not it keeps blowing the FP Fuse), replaced blown fuse, removed FP Relay, did a bypass on pins 87 and 30 to activate the fuel pump and then connected the battery. I heard the fuel pump motor come on and the fuse did not blow. I assume that if there was a grounding issue on the fuel pump side, the fuse would blow.

With that said, I eliminated the fuel pump or fuel pump wiring being the problem. I am going to clean the IPM and the connectors.... maybe buy some dielectric grease. Try testing just the OR/RD wire for ground and then try the other steps you mentioned. Yes, I did find the plug where the OR/RD wire connects to under the IPM. Will see if I can work on it today, if not definitely tomorrow. I want to thank you for all the info you provided and I really appreciated.
 

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Discussion Starter · #7 · (Edited)
Based on what you're telling me; the way I'd move forward is to go to that OR/RD wire at the PCM C1 connector. Either depin it from C1 or cut that wire up about an inch and a half from the connector. (Give yourself room to make a clean repair to the wire after testing.) Then plug C1 back into the PCM. If the fuse still blows, you have a short and I'm strongly inclined to believe it's a wire to wire short it's in another one of the wires coming from C1, whether you can see it or not. If the fuse does not blow, then you've just about proved your PCM to have an internal short.

There is one more thing you can do to test the OR/RD wire for a short to ground. With C1 disconnected, also pull the fuse. This way the wire is totally isolated. Connect your test light to battery (+) and probe the open fuse cavity or OR/RDpin at C1. The test light should stay off. If it lights up, it's because there's a short in the wire. Another option is if you have a multimeter, set it to Ohms and clamp one lead on any clean ground under the hood and put the other lead on either end of the same wire. You should read infinite resistance or OL or whatever your meter's appropriate symbol shows. It's two ways to get to the same conclusion.

In any event that you can prove the short is before the PCM, there actually still is a chance that the IPM is shorted. Or at least the connectors that plug into the back of it could be shorted. Corrosion between two terminals could be acting as a bridge to a ground circuit that just so happens to not have any continuity until C1 at the PCM gets reconnected. You'd be amazed at what can happen with corrosion in a fuse block. If you get to the point you know it's a short in the wiring, at least disconnect C3 at the IPM and check it for fuzzy shit before you open up any of the wiring harness. C3 at the IPM has the other end of your OR/RD wire. The IPM has a couple lock tabs on the side opposite of the battery and then the IPM tilts up on a hinge. I can't remember for sure, but you may have to pull the battery to allow the IPM to fully tilt. WARNING *I forgot that my copy of the factory service manual is limited to 05-07 model years. C3 may not be the right connector for your 03, but do check IPM connectors just the same.

Just curious; did you ever pull the fuel pump relay at any time during your testing?
I couldn't depin the OR/RD wire, so I cut the wire higher up to have room to fix it later. I had a good fuse in the FP and connected the C1 connector back on. I then proceeded to connect the negative cable to the battery and the FP fuse did not blow. I tested the OR/RD wire for ground with the test light and it was't grounded.

Without that wire, the car is still totally dead where it won't crank or the fuel pump will not come on. I don't think that wire would keep the car from starting or cranking... would it? I think the computer is fried. I think I am to the point where I think I am 99% sure the PCM is the problem. What do you think? IPM looked good and connections were good too. The Minivan has been kept inside the garage where it is not exposed to constant outdoor weather.
 

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Without that wire, the car is still totally dead where it won't crank or the fuel pump will not come on. I don't think that wire would keep the car from starting or cranking... would it? I think the computer is fried. I think I am to the point where I think I am 99% sure the PCM is the problem. What do you think? IPM looked good and connections were good too. The Minivan has been kept inside the garage where it is not exposed to constant outdoor weather.
One of the tough parts of diagnosing is trying to find the information as to whether or not that one wire could shut down everything. I can say it's likely that it could and, if it is, it's also plausible that it's by design. If your shematic matches mine, where the FP circuit branches to the PCM doesn't really explain much. What I know of common PCM engineering strategy is that they'll build circuits in just to monitor voltages. In the case of your Caravan, it's plausible that the other end of that wire that seems to pointlessly go to the PCM is actually a monitoring circuit. When the PCM wakes up, it looks for battery voltage on the OR/RD wire and if it doesn't see it, it would assume the fuel pump blew the fuse and prevents engine cranking. In that sense, it could also be a wake up circuit itself. Now that the wire is disconnected, it's possible the PCM doesn't even know it's time to work. Engineers can build a board where parts of it can operate independently of the rest of the board. IIRC, the EVAP monitor in your PCM is an example of that.

What confuses me right now, though, I don't believe your starter is PCM controlled. Regardless of any PCM strategy I mentioned, your van should crank. I don't have time to research it either. When you started diagnosing this, you were only diagnosing a shorted circuit, correct? You could still crank the engine before today?

At this point, I'm also fairly certain of a short in the PCM as well. But given there's no Caravan in front of me to poke and prod, I'm going to say it's your decision as to whether or not you pull the trigger on a PCM. One last thing I'd probably want to do before I order a magic box is to check resistance with an Ohmmeter between the OR/RD wire where you cut it near the PCM and battery (-) or clean chassis ground. Make sure C1 is plugged back into the PCM and see what your resistance is. Even without knowing what a known good or bad value is, I'd be fine seeing 20,000+ Ohms on that circuit. That means the circuit does eventually have a job to do inside the PCM. But if that thing has less than 10 Ohms of resistance, I'd fire a new/salvage yard magic box at it and see what happens. Even if the magic box still needs reprogramming, it should stop blowing fuses when you put everything else back together.

You might be able to plug & play a used PCM into it and it'll fire right up. You have a 2.4 engine, though. For the hundreds of those vans I've seen & worked on, I've only met one or two that came with a 2.4. That means a donor PCM will also have to come from a van with a 2.4. Having said that, I have no idea how hard it would be for you to find a used donor. I'd wager you're safe with 01-03 donors as long as the part numbers on the case match up. 04 is an iffy year to me, but I'd be fairly certain 05-07 model years would not work. Somewhere in that time frame, they changed the PCM's to their NGC types. Anyway, if you can find a donor PCM and your ignition key has a black, hard plastic head, it improves the chances you can start the van without reflashing it. If your van has a key with the grey squishy head on it, that means there's an antitheft system that will allow the car to crank and start just to immediately die. The reflash then becomes mandatory and you'll need to go to the dealer to get a four digit PIN so a tech can reflash it. That assumes you know an independent shop that can do reflashes. If there is no antitheft and a donor PCM has the right part number, the PCM might flag a code for VIN mismatch, but should still let the van start. (Rewriting the VIN does not require a reflash. A capable aftermarket scan tool can do it. I've taken a few turns with various Snap On and Autel scan tools with no issue.) Now that I think of it, if the donor PCM came from a van with antitheft, you need to do the dance with the reflash and the PIN.

Holy shit, I've put too much time into this response. I'm off to cause trouble elsewhere.

Good luck!
 

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Discussion Starter · #9 ·
One of the tough parts of diagnosing is trying to find the information as to whether or not that one wire could shut down everything. I can say it's likely that it could and, if it is, it's also plausible that it's by design. If your shematic matches mine, where the FP circuit branches to the PCM doesn't really explain much. What I know of common PCM engineering strategy is that they'll build circuits in just to monitor voltages. In the case of your Caravan, it's plausible that the other end of that wire that seems to pointlessly go to the PCM is actually a monitoring circuit. When the PCM wakes up, it looks for battery voltage on the OR/RD wire and if it doesn't see it, it would assume the fuel pump blew the fuse and prevents engine cranking. In that sense, it could also be a wake up circuit itself. Now that the wire is disconnected, it's possible the PCM doesn't even know it's time to work. Engineers can build a board where parts of it can operate independently of the rest of the board. IIRC, the EVAP monitor in your PCM is an example of that.

What confuses me right now, though, I don't believe your starter is PCM controlled. Regardless of any PCM strategy I mentioned, your van should crank. I don't have time to research it either. When you started diagnosing this, you were only diagnosing a shorted circuit, correct? You could still crank the engine before today?

At this point, I'm also fairly certain of a short in the PCM as well. But given there's no Caravan in front of me to poke and prod, I'm going to say it's your decision as to whether or not you pull the trigger on a PCM. One last thing I'd probably want to do before I order a magic box is to check resistance with an Ohmmeter between the OR/RD wire where you cut it near the PCM and battery (-) or clean chassis ground. Make sure C1 is plugged back into the PCM and see what your resistance is. Even without knowing what a known good or bad value is, I'd be fine seeing 20,000+ Ohms on that circuit. That means the circuit does eventually have a job to do inside the PCM. But if that thing has less than 10 Ohms of resistance, I'd fire a new/salvage yard magic box at it and see what happens. Even if the magic box still needs reprogramming, it should stop blowing fuses when you put everything else back together.

You might be able to plug & play a used PCM into it and it'll fire right up. You have a 2.4 engine, though. For the hundreds of those vans I've seen & worked on, I've only met one or two that came with a 2.4. That means a donor PCM will also have to come from a van with a 2.4. Having said that, I have no idea how hard it would be for you to find a used donor. I'd wager you're safe with 01-03 donors as long as the part numbers on the case match up. 04 is an iffy year to me, but I'd be fairly certain 05-07 model years would not work. Somewhere in that time frame, they changed the PCM's to their NGC types. Anyway, if you can find a donor PCM and your ignition key has a black, hard plastic head, it improves the chances you can start the van without reflashing it. If your van has a key with the grey squishy head on it, that means there's an antitheft system that will allow the car to crank and start just to immediately die. The reflash then becomes mandatory and you'll need to go to the dealer to get a four digit PIN so a tech can reflash it. That assumes you know an independent shop that can do reflashes. If there is no antitheft and a donor PCM has the right part number, the PCM might flag a code for VIN mismatch, but should still let the van start. (Rewriting the VIN does not require a reflash. A capable aftermarket scan tool can do it. I've taken a few turns with various Snap On and Autel scan tools with no issue.) Now that I think of it, if the donor PCM came from a van with antitheft, you need to do the dance with the reflash and the PIN.

Holy shit, I've put too much time into this response. I'm off to cause trouble elsewhere.

Good luck!
I was looking at this one on eBay for $135 but with the Best Offer option. He also programs the PCM with the VIN, miles and what ever it needs. This would be the 3rd computer I buy. The factory PCM was damaged by a mechanic and I bought a used one reprogrammed. Then after a while I was getting many engine codes and decided to take advantage of the lifetime warranty and get a replacement. This time the PCM seems to have gone out after the car sitting with a bad low voltage battery while jump starting the car. I read that the PCM after so many years and the extreme heat can loosen the solder connection on the chip. Don't know, but I think will make an offer of $100 and see of he takes it.

 

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Discussion Starter · #10 ·
One of the tough parts of diagnosing is trying to find the information as to whether or not that one wire could shut down everything. I can say it's likely that it could and, if it is, it's also plausible that it's by design. If your shematic matches mine, where the FP circuit branches to the PCM doesn't really explain much. What I know of common PCM engineering strategy is that they'll build circuits in just to monitor voltages. In the case of your Caravan, it's plausible that the other end of that wire that seems to pointlessly go to the PCM is actually a monitoring circuit. When the PCM wakes up, it looks for battery voltage on the OR/RD wire and if it doesn't see it, it would assume the fuel pump blew the fuse and prevents engine cranking. In that sense, it could also be a wake up circuit itself. Now that the wire is disconnected, it's possible the PCM doesn't even know it's time to work. Engineers can build a board where parts of it can operate independently of the rest of the board. IIRC, the EVAP monitor in your PCM is an example of that.

What confuses me right now, though, I don't believe your starter is PCM controlled. Regardless of any PCM strategy I mentioned, your van should crank. I don't have time to research it either. When you started diagnosing this, you were only diagnosing a shorted circuit, correct? You could still crank the engine before today?

At this point, I'm also fairly certain of a short in the PCM as well. But given there's no Caravan in front of me to poke and prod, I'm going to say it's your decision as to whether or not you pull the trigger on a PCM. One last thing I'd probably want to do before I order a magic box is to check resistance with an Ohmmeter between the OR/RD wire where you cut it near the PCM and battery (-) or clean chassis ground. Make sure C1 is plugged back into the PCM and see what your resistance is. Even without knowing what a known good or bad value is, I'd be fine seeing 20,000+ Ohms on that circuit. That means the circuit does eventually have a job to do inside the PCM. But if that thing has less than 10 Ohms of resistance, I'd fire a new/salvage yard magic box at it and see what happens. Even if the magic box still needs reprogramming, it should stop blowing fuses when you put everything else back together.

You might be able to plug & play a used PCM into it and it'll fire right up. You have a 2.4 engine, though. For the hundreds of those vans I've seen & worked on, I've only met one or two that came with a 2.4. That means a donor PCM will also have to come from a van with a 2.4. Having said that, I have no idea how hard it would be for you to find a used donor. I'd wager you're safe with 01-03 donors as long as the part numbers on the case match up. 04 is an iffy year to me, but I'd be fairly certain 05-07 model years would not work. Somewhere in that time frame, they changed the PCM's to their NGC types. Anyway, if you can find a donor PCM and your ignition key has a black, hard plastic head, it improves the chances you can start the van without reflashing it. If your van has a key with the grey squishy head on it, that means there's an antitheft system that will allow the car to crank and start just to immediately die. The reflash then becomes mandatory and you'll need to go to the dealer to get a four digit PIN so a tech can reflash it. That assumes you know an independent shop that can do reflashes. If there is no antitheft and a donor PCM has the right part number, the PCM might flag a code for VIN mismatch, but should still let the van start. (Rewriting the VIN does not require a reflash. A capable aftermarket scan tool can do it. I've taken a few turns with various Snap On and Autel scan tools with no issue.) Now that I think of it, if the donor PCM came from a van with antitheft, you need to do the dance with the reflash and the PIN.

Holy shit, I've put too much time into this response. I'm off to cause trouble elsewhere.

Good luck!
I forgot to answer your question about the cranking. It was cranking when I was jump starting it and then something happened, when I went to start it again when I notice the fuel pump did not prime and the car did not crank. If I remember correctly, when the mechanic blew the factory PCM.... it was similar where the car was dead and did not crank or do anything. I know when I was working on a 96 jeep cherokee my father bought.... the car did crank and would not start. We troubleshoot everything from the crank sensor, timing, fuel pump, sparkplug rotor, and coil... etc.. and in the end it ended up being the computer. Thats when we started getting sparks in the sparkplugs and we then could get it in timing and is running great.
 

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At this point, there's nothing more I can offer. Keep us posted when you have something new to share. I'll stay with it if/when I can.

Good Luck.
 

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Discussion Starter · #12 · (Edited)
At this point, there's nothing more I can offer. Keep us posted when you have something new to share. I'll stay with it if/when I can.

Good Luck.
I Ordered the PCM from eBay and got it Saturday in the mail. I couldn't work on the car until today. I fixed the spliced OR/RD wire and as soon as I connected the battery the FP fuse did NOT blow. It used to blow immediately. Car now turn on and is working fine. I guess the PCM replacement I received back when the original was replaced may have been a repaired PCM and was probably not well repaired. This one is from a Junk yard salvage place that was reprogram with the VIN and miles. All is working well. Thank you for helping me out and for your wise advice.
 

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I guess the PCM replacement I received back when the original was replaced may have been a repaired PCM and was probably not well repaired.
IMHO, Mopar electrical & electronic components are not well manufactured new to start with. With most other manufacturers, you usually want to think about blaming a module like a PCM last in your diagnostic strategy. With a Dodge, it ranks right up there with wiring, ground, and corrosion problems. For what that's worth, it's sometimes hard to tell if or when one problem didn't cause the other. They really are that problematic across the board. I've had a cooling fan relay shut down a transmission on a Chrysler Pacifica. I once found a near microscopic pin hole in a CAN-BUS wire that shut down at least three modules in Jeep. Examples like those were why I was Hell bent on verifying the condition of the IPM, the FP relay, and the wiring underneath the IPM. The diagram I was looking at showed your OR/RD wire terminates at pin 20 on C3 and the FP relay control wire isn't too far away on pin 8. I've seen corrosion bridge pins and cause similar problems. That kind of corrosion could very well happen inside the relay itself. As a matter of fact, that's how a cooling fan relay almost killed a Pacifica. If I ever had to own a Dodge, the moment it turned eight years old, I'd start load testing all my grounds at every oil change and replace the IPM/TIPM just out of spite.

At any rate, I'm glad to hear you're back on the road.
 
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