Shut off while driving

Sounds like the PCM has failed. However, we need to check the voltage from at the DLC on pin 7 to ground when the key is on. This is the SCI bus that needs to communicate through the DLC in order for the scan tool to communicate with the PCM. Also, we need to check pin 2 and ground to find out what this voltage is as well.

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-use-a-voltmeter

I am attaching the wiring diagrams below for your reference. Please let me know what questions you have and we can go from there.

Thanks

Okay, so I checked pin 7 to ground = 9.6.
Pin 2 to ground is shorting out.

When you say shorting out, do you mean you have no voltage or did you check continuity to ground?

This is your PCI bus connection so that explains why you cannot communicate.

What I would suggest is disconnect the modules on PCI bus and see if unplugging one of the modules causes the communication to come back.

If it does then that module is your issue.

I would suggest starting with the PCM. Also, you should check the junction port that is under the left side of the dash and make sure it is connected and doesn't have corrosion.

See video pin 2 to ground.

Okay. That is great info. Basically you have .3 volts which would indicate a short to ground.

I assume this was with the key on? If it was then we need to do a little more testing. If the complete bus is down then you should not be able to communicate with any module. Otherwise you may just have an issue with the PCM.

Does your scan tool have the ability to communicate with individual modules?

I attached the testing and info below on this but basically we need to find out if it is just the PCM or the entire network to find out next steps.

As you will see each module has the ability to communicate on their own unless the entire bus is down.

Please let us know what questions you have.

Thanks

Hi, and first of all I want to say thank you for all the help. My vehicle harness doesn't have a junction port with individual connection for each module. It have two test port one for obd2 and one for dbr3 scan tool, when I unplug a cover that the bd3 plug have, the odometer say no bus! Once I plug it back in the no bus, goes away.

Can you get a picture of this cover? I am pretty sure I understand what you are referring to but this is expected. By unplugging that connector, you are opening the bus network removing the PCM and it says no bus. Basically this is taking the bus down which is why I am thinking we have one module that is the issue.

Hello, I am at work, once I get home I will take a picture. how much trouble will be if we can talk on the phone?

Hello, here are photos and a video of what the gauge does. The connector on the left is the DBR, and the right is the OBD2.

Unfortunately we don't have a phone service. We are a free service that provides this info online just so that others that have the same issue can follow along. Sorry about that.

The photos did not attach if you can try that again but just reviewing this, I think we may have gone down a rabbit hole.

If you have no fuel or spark and no communication to the PCM then we need to tackle this. I doubt the entire bus is down or it would say no bus in the cluster.

This means our issue is most likely with just the PCM. When you said you checked power and ground for the PCM, was that at the PCM that you checked and did you check all the B+ and grounds for the PCM?

If you did and you have 12 volts then the PCM is most likely the issue as it has a short. At this point, there are many services that will rebuild your PCM for you on this truck and that is far cheaper and easier then replacing it.

Basically if the PCM is not communicating and it has power and ground and the bus is intact, then on this specific network, that module is the issue.

Each module on this bus as its own voltage and termination which simply means they are stand alone modules and if it fails it does not take down the entire bus like on some other networks.

I have order a PCM from flagship1, which I will not recommend, due to service been delayed for 3 weeks now. I have been looking around and for some reason this particular model of PCM is hard to find, talk about bad luck.

I have a ton of contacts with Mopar, can you provide the last 8 of your VIN and I will get the OEM part number and see what I can track down?

Thanks for the update.

Hello, sorry I haven't posted lately just been busy. Good news I got my money back from flagship1 and reorder a PCM from California, it arrives today I plug it in a truck fire right up, took it for a test drive, and runs fine, I thank you all for the support and if I can answer any questions just let me know.

That is great information and I am happy it worked out for you.

That info is definitely going to help others in the future so thank you for helping to make this site better with the follow up.

Clearly not necessary but if you can to post a review of the 2CarPros at this website, it will help spread the word. Thank again for coming back to update us.

https://www.sitejabber.com/reviews/2carpros.com