06 GTO LS2 E40 Swap No Crank/Start

Doing a transplant using a donor 2006 GTO LS2 engine/t56/E40/harness all from the same vehicle. I wired the C1 connector (Blue) for the vehicle connection. First attempt at Crank got no cranking and a P1629 vehicle theft DTC. I then had the ECU flashed locally using EFILive to remove the VATS. Same "no crank" situation but no P1629 this time.

I think I have the C1/Blue connector wired correctly but how would I know?

Does anyone have the minimum set of wires required for an E40 ECU to start?

For an LS2/T56, is there a TCM? Does that generate the ParkNeutral signal?

Is it the Crank purple wire that tells the ECU to ground the "clutch pushed" circuit?

What other signals does the ECU look at in order to Crank?

Thanks!

You would have to verify the connector pin-by-pin wire-by-wire against a reliable wiring diagram/chart (testing continuity between connector ends).

I'm not sure what are the required minimum required wires.

T56: no TCM.

Manual trans: CPP (clutch pedal position) switch determined P/N (clutch disengaged/freewheeling corresponds to P/N).

What is the purple wire...?

What signals do you have and what signals don't you have...?

Are you saying the P/N signal on a manual transmission is when the clutch is pushed in? Is that a voltage signal?

The purple wire on the C1 connector is labeled on the schematics as Crank. I assume that to be the Start signal from the ignition switch. Yes?

Yes, clutch pedal pushed in ("clutch disengaged") correspond P/N tables in ECM (typical idle and A/C tables).


2006 GTO:
C1-52 PU is crank voltage, hot in START and ON positions (on the engine controls schematic)
C1-43 PU/WH is clutch position switch (on the cruise control schematic)

[ PU = purple, PU/WH = purple with white stripe ]

C1 #52 is crank voltage hot in run? I read it as hot only in Start? If not, is there a signal to the ECU for START? Or is it just the starter cranking and the ECU follows?

Thanks.

My diagram shows it hot in START and ON/RUN.

I believe the ECM sees pulses from the CKP sensor.

Thanks for that clarification. What do you see regarding the Park/Neutral signal on a manual transmission? Not used or GND at all time?

I'll have to take another look later tonite...

I bought my own copy of EFI Live GM Gas yesterday. So my next atep is to use it to help debug why I can't get this LS2 to start. Any suggested EFI Live tools/methods or procedures I should do first to help debug this?

BTW, I did trace down the C3 #22 pin and it does not exist on a manual transmission LS2 GTO wiring harness.

Log the STATE pids to see if VATS is disabling the start.

Success. The tuner who removed the VATS did not apply the patch. With my own copy of EFI Live I was able to do that and it started immediately.

Thanks for the help along the way.

Cool :cheers:

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