No Bus signal

19STORMGSI90

MEMBER
2007 DODGE MAGNUM
3.5L
V6
2WD
AUTOMATIC
123,000 MILES

Driving down the road and all gauges and wipers went crazy then car shut off. Battery ended up coming unhooked and now it says no BUS and nothing works. It will start and drive but it is not right. Also the ABS fuse blows every time I put one in. I was told it was the PCM so I bought a new one and it still wont work.

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

Sounds like we could have a couple issues on this one but let's start with the no bus communication.

This is a network that all your modules communicate on. So, the fact that it says no bus just means that either the PCM or cluster is not able to communicate properly.

Here is a guide that will help with this:

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

We need to start with checking for codes and here is a video that will help with doing this on this type of system:

https://www.youtube.com/watch?v=InIlnsjOVFA

On this system we need to start with doing what is called a termination resistance check. You do this by disconnecting the battery and checking the resistance between pin 6 and 14 of the DLC under the dash.

This should be 60 ohms give or take a couple. If it is 120 or something significantly different, then we have an issue with one of the two terminating modules which is the cluster and ECM. If the resistance is not exactly 120 ohms, then we need to unplug the ECM and Cluster and see when it goes to 120 ohms. Basically, each module has a 120-ohm resistor inside of it so the one that is causing the issue when unplugged, the resistance of the other module will read 120. So, you can switch them, and you will get the other module reading something much different which is what is causing the issue.

Please run through all this and let us know what you find because there may be a wiring issue or other issue that we will need to dig into.

Thanks

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