2JZ Speed cut issues. Have defender fitted but sometimes cuts.

[CrUZida]

Ahh, sorry, missed this line

Its a slave to the trans speed signal and has no bearing to what the ECU sees.

Generally the trans speed signal is only used when the main speed signal fails.
ie, the 2 wire jobbie on the back of the gbox is the slave signal, and the main one is the one that goes to the dash.

[2JZR31]

What I meant by "slave" was the speedo correction part of my circuit does nothing to the signal the ECU sees. It just runs the speedo. The SP1 signal just goes straight to the ECU via the SCD. It doesn't get "corrected" then head to the ECU. My speedo requires over twice the pulses so if I did send this corrected signal to the ECU I would most likely get a SP1 error code, or my speed cut would be at 90km/h

I suppose if you did the correction then sent the signal to the ECU the speed cut could occur before the change into 4th.

[CrUZida]

Ah k, I see where you are coming from. I was forgetting about the whole R31 thing, and it requiring a much different signal to what the sensor is outputing.

Yep, totally agree then.