Gen 4 Ecu in 66 Chevy truck, which trans computer to run

[Howedeman]

Most of my experience with HPT has been with the Gen 3 ECUs. I am building basically a LS7 to put in a 66 Chevy truck. The customer wants to use a Gen 4 ecu so that he can have cruise control and be a cleaner setup. The trans will be a 4L60. When I talked to the guy that makes the cruise box and harness he suggested starting with an 09 Corvette with 427, E38 ecu. He mentioned he normally likes to use the TCI trans controller instead of the factory. I think the TCI would be simpler but I sure like being able to look at the logs for both the engine and trans. So...which factory tcm would be the best for this application. Also if we ended up switching to a 4L80 would I run into any problems. I believe that if I started with a truck ecu/tcm combo it would work fine but 'im sure the corvette data would be a lot closer starting out. The engine is not a LS7, but is a 427 with Brodix BR7 heads and new factory LS7 intake assembly. I have been away from tuning with HPT for a while and I was glad to here the new version has the capabilities of tuning the VVE now! Let me know what you think, thanks!

[DSteck]

You need a T42. You can run a Corvette OS in the ECM.

I'm curious to hear about the cruise box. I assume it's a BCM replicator.

[Jon S.]

Guessing cruise control will be a Rostra setup. These connect in line with the APP, and fake an APP signal to the ECM to maintain speed. Depending on the platform, you may get intermittent limp mode issues.

My two cents is that using an E67 (if possible) is the best option for cruise control with a Gen 4 engine.

[DSteck]

Why E67 over E38? Both will need CAN signals from what it thinks is a BCM to activate cruise.

[Jon S.]

Why E67 over E38? Both will need CAN signals from what it thinks is a BCM to activate cruise.

Some E67 platforms used a direct input to the ECM for cruise control (no BCM / CANBus involvement).

[DSteck]

Hmm. I've scoured wiring diagrams and have never found one that does. I'll have to look again.

[Jon S.]

Trailblazer is the E67 platform most often used for direct cruise input. Some other E67 platforms used a ladder resistor arrangement (like a tap shift switch) as the direct cruise input.

EFI Connection sells (or used to sell) a cruise box that had the ladder resistors built into a circuit board.

[Howedeman]

The cruise control is by Hot Rod Therapy. His name is Adam Gunn in Arkansas. He says the E38 has always worked with out any problems. Some how it ties into the pedal signal. No BCM required. I believe he was either the first or one of the first to get this to work. He seems pretty knowledgeable about what he is doing. If I was to use the T42, would I have any issues if I switched to a 4l80, other than changing some wires. The trans is out of a 02 Firebird with 20,000 miles. Completely stock. The engine should make in the 600hp range. Later it may get a Magnuson or a Whipple so may have to change trans. I am not too familiar yet on the different TCM's

[Howedeman]

I do not have any of the electronics for this yet, what are the preferred coils and part numbers for the 09 corvette system? It seems like there are so many different coils these days.

[DSteck]

There's two operating systems with the same ID that run the 4L60 and 4L80. You'll be fine.

[Howedeman]

Thank you, do you know which ones those are? The operating system I have been looking at is 12612384. At least for the ECU. Do you know the specific vehicles I should look at for these tunes?

[Howedeman]

What is the correct procedure for changing just the trans part since it reads the ECU first, then the TCM. I have heard of pulling the tcm fuse to do the ecu, then pull the ecu fuse to do the tcm. I have only played with 1 Gen4 and it was a cam only change.

[DSteck]

3.4 lets you read and write modules individually.

[DSteck]

Trailblazer is the E67 platform most often used for direct cruise input. Some other E67 platforms used a ladder resistor arrangement (like a tap shift switch) as the direct cruise input.

EFI Connection sells (or used to sell) a cruise box that had the ladder resistors built into a circuit board.

Sure enough, Trailblazer E67 is direct cruise input. The 2007 CTS-V is also direct input, although it uses the resistor ladder.

[Howedeman]

3.4 lets you read and write modules individually.

Very good, thank you! Looks like I need to update software and go hook up to something and do a little updating my self.