Question about converting loom

[philkensebben]

Hi all,

Currently knee deep in converting a VS 304 Auto loom to suit a 808 T5 (for my VS). All is going well, auto connector has been removed, plugs modified to fit into the ECU, I’ve worked out most of the repinning but there are currently two questions I have:

1. Using the Hall effect speed sensor, I can see that most just send the signal direct to the cluster and don’t send anything to pin A10 on the 808. What is the negative from this, and is it possible to simply send the signal to the 808 or does it have to pass through the cluster first (the wiring diagram seems to think so). Goes into the cluster violet/white and comes out brown/yellow apparently.

2. Does anybody know what pin A12 on the VS PCM is, it’s not referenced in any document I have and it connects to the plug that goes to the cluster/bcm/diag port.

Cheers!

[pman92]

With the 808, the speed signal originally went to the cluster where it went through a divide circuit (something like 10 pulse per revolution to cluster, and then cluster sent a 2 pulse per revolution signal to ECU).
You can hook it up directly to ECU, but the PPK value must be changed in the calibration or the ECU will think the speed is 5 times what it really is (Will cut out once reaches 250 km/h because of speed limiter etc).
If your tuning its not hard to do

[pman92]

Pin A12 on VS V8 is listed as unused in the factory manual I have

[pman92]

A12 is the brown/white wire correct?
If so definitely unused so can be deleted

[philkensebben]

You can hook it up directly to ECU, but the PPK value must be changed in the calibration or the ECU will think the speed is 5 times what it really is (Will cut out once reaches 250 km/h because of speed limiter etc).
If your tuning its not hard to do

Legend! I will be using the $12P tune so I can alter that in the ECU without a problem. In that instance would you just splice the signal wire from the sensor into both the ECU and cluster wires?

A12 is the brown/white wire correct?
If so definitely unused so can be deleted

That's correct, so it's just a wire put in there for something at a later date?

[VL400]

A12 on the VS PCM is for V6 only, cranking input to help stop backfires with the wasted spark ignition if its cranked but does not start. Its B2 on the '808 but you wont need to worry about it.

[philkensebben]

A12 on the VS PCM is for V6 only, cranking input to help stop backfires with the wasted spark ignition if its cranked but does not start. Its B2 on the '808 but you wont need to worry about it.

Brilliant thank you!

In regards to the speed setting in the tune, I took a look and found the "Road Speed params" scalars with the setting for the PPK in there. Just to confirm my thinking it will be:

(1000/1.68m) * 3.7 (or 3.46 I can't remember right now what I put in) * 10 (because we're using the signal direct from the sensor not the cluster).

Edit: 1.68m based off the tyre circumference of the R16 on there.

[Holden202T]

yeah it should be multiply by 5 to get the number without the dash divider, then offset from there for your gears.

once its driving then compare the dash and/or GPS to what you see in the tune to get it right.

[philkensebben]

yeah it should be multiply by 5 to get the number without the dash divider, then offset from there for your gears.

once its driving then compare the dash and/or GPS to what you see in the tune to get it right.

Perfect! Thank you for the help I'll keep pressing on with this re-pinning.