I searched and couldn't find what I'm after. I just had an '05 GTO LS2/T56 installed in my Canadian spec '86 IROC by a local speedshop. I have all the original gauges in the car. Had to use an adapter for my cable speedo to work. Engine looks great with excellent performance but there are some issues.

1. They tell me cruise control won't work since I have the DBW system. They said Hawk's Thirdgen confirmed this.

2. The stock temp gauge (celsius) in my car is almost always pegged high. They cannot figure this out.

3. The stock tach isn't working yet. They said Hawk's Thirdgen says I need an adapter of some sort to make it work. It's on order.

If anyone can shine any light into these areas, I would appreciate it. I'm the type of guy that likes to have everything working. Please try to answer in lamens terms as much as possible so I can relay it to the shop. Thank you.

 

both of the guages are done through the c100 connector on the driver side, so you may want to check how they tapped into things. The tach should work, even if its off (due to different programming). coolant temp will require A: getting a 98 LS1 coolant temp sensor and wiring up the additional wire to the guage or B: adding a sensor just for the guage output.

 

Hawks speaks the truth. I'm going through similar pains with the '06 version destined for my '86 too. From what I have been reading Cruise Control is controlled via the PIM(Powertrain Interface Module) which sends the commands to the PCM in CAN(Controller Area Network or something like that) speak. The PIM won't work without all this fancy syncing stuff to the BCM(Body Control Module) and the BCM won't do anything without authorization from a sync'd PassKey key. What I am saying I guess is that If you did not get the steering column with key and the modules I just listed from the donor car you probably will not be able to get the factory digital cruise control that is part of the GTO's features working. I feel your pain.

Mike

 

I guess I should have asked in my previous if you know which ECM the speedshop used to interface in swap. If they used the E40 that was in the GTO then what I said is correct. If they used an aftermarket standalone harness with an LS1 ECM then the diagnosis is different.

BTW I believe another gotcha with the GTO E40 is the control of the radiator fans with the ECM. It is expecting the A/C Request signal to also come in on CAN.

Mike

 

1) Just hook the wires up. Cruise is directly linked in with the TB and TAC module. It has no connection to any outside modules

http://www.lt1swap.com/dbw.htm

2) Did it work properly before the swap? What sender is feeding the gauge

3) Tach is easy. Hook it up directly from the PCM. If the value is wrong, adjust the output frequency in the tune. If it doesnt move at all, use a booster wire

http://www.lt1swap.com/lsx_tach.htm

Personally, Id go back and tell the shop to finish the job

 

If the GTO E40 is being used there is no separate TAC. It is built in to the ECM for both 2005 and 2006 GTO.


Unfortunately the 2005 and 2006 GTO get their cruise commands via the PIM which only talks to the ECM in CAN. Now we are back to needing the BCM and PassKey for all to function.


These are part of the difficulties of why I am shying away from using the E40 that comes with the goat motor.

All this is moot if another variety controller was used by the shop for the install. Which ECM is being used is a priority question. I apologize if I seem argumentative.

Mike