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Old Feb 4, 2021 | 05:09 PM
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When Global B was first announced and there was talk of communications encryption, I thought it was the end all mods. However, apparently every think is not encrypted, as we have had several electronic mods come out:

A magnetic shock control unit that adjusts shock response curves.
Exhaust valve fake out.
A module to adjust throttle response.
Throttle body (maybe the electronics are the same?).

So clearly those things did not have encrypted communication. Maybe it is just between the ECU, TCU, BCM?

What other things don't have encrypted communications? Or what does, if that is easier.


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Old Feb 4, 2021 | 05:38 PM
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The encryption is between different modules on the data buses. It's got nothing to do with the signal IO between a module and its sensors and actuators.

Tuners have had some success feeding fake values to the ECM to support some mods. But the question is how far can you push those fake values before you start tripping on the sanity checks the ECM has for those values.

Last edited by Jeff V.; Feb 4, 2021 at 05:39 PM.
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Old Feb 4, 2021 | 05:57 PM
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Originally Posted by Jeff V.
The encryption is between different modules on the data buses. It's got nothing to do with the signal IO between a module and its sensors and actuators.

Tuners have had some success feeding fake values to the ECM to support some mods. But the question is how far can you push those fake values before you start tripping on the sanity checks the ECM has for those values.
I figured as much. What modules are on the data bus?
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Old Feb 5, 2021 | 10:43 AM
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Originally Posted by Racer X
I figured as much. What modules are on the data bus?
All of them

There's 11 different CAN buses and an 5 ethernet buses. There's also a bunch of LIN buses, but those are really unlikely to be encrypted.

To add to the fun, there's a gateway module. All the pins on the OBD port go through the gateway. The gateway is a firewall that filters traffic from one bus to another, and also locks down the OBD port.

So if you want to try to program the ECM for example, you're going to have to get permission from the gateway before you can even start to talk directly to the ECM.

Or you can pull the ECM out of the car every time you want to make a change. Just have your jack handy. It's underneath the car in the center tunnel.

Last edited by Jeff V.; Feb 5, 2021 at 10:44 AM.
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Old Feb 5, 2021 | 03:25 PM
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Originally Posted by Jeff V.
Or you can pull the ECM out of the car every time you want to make a change. Just have your jack handy. It's underneath the car in the center tunnel.
I suspect the key exchange encryption would make communicating with a removed ECU as hard as getting through the gateway in the first place -


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Old Feb 5, 2021 | 04:13 PM
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Originally Posted by Jeff V.
All of them

There's 11 different CAN buses and an 5 ethernet buses. There's also a bunch of LIN buses, but those are really unlikely to be encrypted.

To add to the fun, there's a gateway module. All the pins on the OBD port go through the gateway. The gateway is a firewall that filters traffic from one bus to another, and also locks down the OBD port.

So if you want to try to program the ECM for example, you're going to have to get permission from the gateway before you can even start to talk directly to the ECM.

Or you can pull the ECM out of the car every time you want to make a change. Just have your jack handy. It's underneath the car in the center tunnel.
So basically we are limited to sensor side adjustments, that work until the ECU has enough and protection decision points move to protect parts, like RPM fuel cutoffs, torque limiting to protect the known trans limits. I am surprised those experimenting with turbos, haven't already hit those. Maybe once GM Parts gets an opportunity for a crate engine, maybe we can get a standalone ECU that can be adjusted.
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Old Feb 5, 2021 | 05:20 PM
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Originally Posted by RedLS6
I suspect the key exchange encryption would make communicating with a removed ECU as hard as getting through the gateway in the first place -
Yep. I only mentioned the gateway because it's just another ECU you need to crack if you want tuning via the OBD port.

Originally Posted by Racer X
So basically we are limited to sensor side adjustments, that work until the ECU has enough and protection decision points move to protect parts, like RPM fuel cutoffs, torque limiting to protect the known trans limits. I am surprised those experimenting with turbos, haven't already hit those. Maybe once GM Parts gets an opportunity for a crate engine, maybe we can get a standalone ECU that can be adjusted.
I really wonder what those cars drive like in the real world. So far all I've seen is dyno pulls or very short street pulls. I doubt a crate engine will fix it. As best I can tell, the LT5 crate uses the same locked down E99 as the ZR1. You'd still need to send it off to HPT for the $2500 modification service if you wanted to custom tune it. I don't see why LT2 will be any different. I really don't see a point in offering a crate LT2 anyway. A very lightly modded LT1 will get you all the same benefits at a lower price point and with an easier install. I'm way more interested in whether or not they'll offer the transaxle in a crate format. That opens up a lot of options for kit cars.
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