Vz sv6 sometimes not starting

[Chris10]

Hi everyone my vz sv6 hasn’t been starting properly lately. If I put my key in and turn sometimes there’ll be either no crank, Sometimes car will turn on and engine will turn off after a second, Other times the car will turn on fine after putting key in and out over and over. I’ve got fuel gauge error, service vehicle soon on my dash and the scan tool says this code U0100. Do I have to get my ecm replaced or fixed and does anyone know how much this should cost around?
Thanks

 

[Jolls]

Hi Chris

Sorry not enough data to provide a solution for you.

U0100 is a comms error between the ECM and TCM. It doesn't necessarily mean the modules are stuffed not does it necessarily mean all of the DTCs have been identified. The multiple symptoms indicate that there are likely a few issues going on. It could be a data transmission issue, a failing module or simply the neutral safety switch playing up.

What scanner did you use to check the DTC? Were there any other DTCs shown as history?

I highly recommend as the first step that you download the VT-VZ manual so you can look up the DTC and then follow the diagnostic charts to identify the fault and complete the repair. You should be able find a link to the manual here

Get in and learn how the modules communicate with each other and what data they rely upon. A read of the system description usually points you in the right direction

Second - if intend to keep/restore the beast can get hold of a quality scanner and get into all of the modules and see what is going on. Check and clear the DTCs one by one. You may find that fixing one will fix several.

So armed with the scanner and the manual you should be well on the way to a solution. If you get stuck or need support simply jump back on here and trust that one of the smart guys are about to provide some support.

They have helped me significantly in during my restoration projects.

Cheers n Beers
Jolls

 

[Fu Manchu]

This one is a deeply complex issue. We’ve suffered with it for years now on the sedan and time does not allow for getting to a resolution.

Recently a member solved theirs with a new oil pressure sensor and crank angle sensor. That solved their similar issue but yours might be different.

The work around is to jump the starter relay.

 

[shueardm]

check the negative terminal of the battery for corrosion. ( you'd be surprised what that can do )