I know that the VAFC is passive in regards to the TPS signal it recieves. It does not manipulate the TPS signal. This means that the VAFC cannot be the problem, as it has no effect on the TPS whatsoever.


There may be a problem with the wire your splicing getting grounded somewhere, check the lengths of wire for your ECU's TPS wire, as well as the VAFC for any opening in the insulation exposing copper.

If nothing was wrong before the install with the TPS, it has to be due to something which occured during the install. If you don't find anything wrong with the wiring, it may be a faulty TPS sensor possibly due to damage which may have occured from it being accidentally grounded or recieving current when it was grounded etc... If the batteries negative cable was removed, this is not the case; it would have to be a bad unit (VAFC). It may be internally grounded and will need to be replaced.