Dave, you can use the MIL output and Low Speed fan output on the PCM, Holden only used serial data to commonise (sp?) the BCM / engine looms between the V6 and the GenIII.
ALL the ins/outs on the US PCM diagrams are available on our local PCM's, just because Holden don't show them doesn't mean they aren't there!.

Cheers,
Ross