chaseb9

Hey guys I need some serious help with this issue my car is having, I just finished rebuilding my torque tube and camming the car and had it started up a couple of times while finishing bleeding the car. I turn off the car and it wont start again.

This is where I am so confused. I try and use Tech2 to read BCM, EBCM, ECM, VCIM. No communication with any module. I replaced BCM no help with issue still no communication. Checking resistance on CAN network shows 1ohm which is not right. TO even see a remotely ok ohm reading I have to unplug the X184 connector next to the ECM cutting off the ECM, EBCM, AND TCM from the can network. This will give be 120ohm reading and give me access to read the codes in the BCM. Now checking voltage with this connector off I get 2.6v on both CAN High and CAN Low. When I connect the X184 connector back in I get 5.004v on CAN High and CAN Low. To remedy this voltage issue once I unplug the ECM it will go back down from 5v on both high and low but I will still read 1 ohm on the CAN network. The ecm ohm reading is fine, I checked the pins directly on the ECM 121ohms. I think CAN High and CAN Low are shorted together somewhere between the X184 connector and the TCM connector. Unplugging the TCM and reading the ohms still shows 1 ohm meaning it has to be something between that and the X184 connector. Which that entire harness runs overtop the torque tube. I am not sure if I am right but I need input on this. Should I just cut the CAN High and Low Wires and make my own 4 going from the X184 Connector to the TCM connector? I am seriously lost. I am replacing ECM tomorrow to see if that helps anything but that ECM is BRAND new from GM, only 3 months old.

yeller z06

As we say in the BMW forum, it's always the battery. Before you start cutting and splicing wires, buy a new battery. Then, if that doesn't work, if you recently replaced the torque tube, and messed with or even looked at that harness goes over the TT, then I'd start looking at every harness that you even saw, much less might have unplugged, in the recent work, and double-check everything. Because it's not because a module has coincidentally gone bad, it's all related to what you just did. Or it's the battery.

Best of luck!

chaseb9

Definitely not battery, wouldn’t cause the ohm readings to be busted on the can network. I’m not entirely sure how I’d damage the wiring, it worked perfectly fine for a bit no issues then just wouldn’t start again.

Landru

Read this recently posted thread: [Help] No crank, No function - CorvetteForum - Chevrolet Corvette Forum Discussion
Sounds familar, no?

Whatscooking

Quinky dink, a buddy I was a mechanic with would call this. Something you have touched or pulled on has plugged up your wiring.

BrandonM7

Sounds like you probably pinched a wire/harness when you put the torque tube back in. That would be the easiest guess, since you just had it out and the harness in question runs over the top of it. I'd try what you suggested (running my own wires instead) just to see if it worked, but then if it did I'd probably find myself pulling the torque tube back out just in case I have some others pinched that I just haven't realized yet. Seems like you've troubleshot the issue very well to me.

chaseb9

Definitely familiar, but I can go into accessory mode, and have complete communication on the class 2 network. So confusing…

chaseb9

Yeah… I think that might be the way to go, it’s gonna have to be me cutting the can lines at the transmission plug and the X184 plug…. Now if that works I think you can replace the harness without pulling the tube which I definitely do not want to pull that stupid tube again, but if I can’t im just gonna stick some wire loom over those wires and run it next to the harness :/. What ever works works. If any other wires are pinched I’ll get codes for them. Hopefully..