I have made some progress with this obsession. OK, All Eurovans have OBD (on
board diagionstics) systems that can tell you problems with engine sensors. 

I even know how to get the system into the right mode. There is a small wire
harness with connectors that fit into the sockets above the fuse box. if the
key is on OFF when the harness is pluged in the system will give out blink
codes when the key is turned ON. If the key is turned ON while the harness
is plugged in the codes will be erased.

Some (cal only cars) even have an engine MIL (malfunction indicator light)
light that can be made to blink out stored fault codes. Non-cal cars do not
have the MIL light and have no way of reading the blink codes.

After going over many books at the dealer with one of their mechanics I have
come to two possibilities:

1. Non cal cars do not have the capability to give blink codes.

2. They do but the wire location is not documented.

I will try one last thing that was sugested by the mechanic: Use a digital
logic probe to find the pin on the ECU that reads out the blink codes.