Project idea for an electronics whiz

[JoshH]

I wonder if any of the smart members we have here might be interested in making a device for me. I'm not sure exactly how it would need to work, but I know sort of what I want it to do. I don't think it would be especially complicated to make, but I could be wrong. I'll explain what I know, and maybe someone will be able to tell me more.

One of the projects we have been working on here in the shop off and on for a while has been building an 03 half ton Silverado with a frame from a 2010 half ton and an L5P engine controlled by an LBZ ECM. We used an electronic power rack and pinion from a 2015 half ton and verified that the rack will operate when the CAN wires are connected to an ECM in a truck that is running (connected to an LBZ ECM). What I'm trying to find out is if someone can build a box that puts out whatever signal it is to say the engine is running whenever the box is powered on. Does this seem as simple to someone who really knows what I need as it does to me? If you have the knowledge to make something like this and are interested, please let me know so we can work out some details.

 

[2004LB7]

This looks right up Ken's alley. Would have to capture the canbus signal and the maybe play back the various bits until the rack responds. Might be as simple as an RPM signal. Or more complicated with a custom message. But once figured out would be easy to make

Does it work with the key on but engine off? Or does the engine have to be turning?

If I'm not mistaken, Ken already has a canbus translator that might be able to be modified for this purpose. Just need to know what message to send

@kidturbo

 

[JoshH]

This looks right up Ken's alley. Would have to capture the canbus signal and the maybe play back the various bits until the rack responds. Might be as simple as an RPM signal. Or more complicated with a custom message. But once figured out would be easy to make

Does it work with the key on but engine off? Or does the engine have to be turning?

If I'm not mistaken, Ken already has a canbus translator that might be able to be modified for this purpose. Just need to know what message to send

@kidturbo

Engine has to be running. We tried hooking it all up to the project truck and turning the key on, but it wouldn't operate. Since the truck didn't run at the time, we extended the wires and plugged them into the CAN wires of the OBD port on a running truck we pulled up next to it. We turned the key on in the project truck to power the rack and turned on the key without starting the engine in the truck with the running LBZ, and we got no power steering. Once we started the engine of the running truck, the power steering came alive.

 

[2004LB7]

Engine has to be running. We tried hooking it all up to the project truck and turning the key on, but it wouldn't operate. Since the truck didn't run at the time, we extended the wires and plugged them into the CAN wires of the OBD port on a running truck we pulled up next to it. We turned the key on in the project truck to power the rack and turned on the key without starting the engine in the truck with the running LBZ, and we got no power steering. Once we started the engine of the running truck, the power steering came alive.

That makes me think, it's probably looking for an RPM signal

 

[kidturbo]

I heard my name and CANbus?

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[JoshH]

I heard my name and CANbus?

Sent from my SM-S901U using Tapatalk

Sound like a project you might like to tackle?

 

[kidturbo]

Hardware wise, we can test all this for $50. Some off the shelf hardware I've been playing with T87 mods. So I took a look at some LML chassis data, and found an EPS node that was spouting some steering angle data. That lead to a list of who it's Transmitting this data to. Along with a very long list of possible RX signals, most of which are brake or EBCM wheel speed related. So that migh be our missing link.

I wouldn't think a steering unit would require much data operate happily. Most likely some Speed, EBCM or BCM messages, not in the LBZ chassis. Take a little trial an error, but according to the CAN specs, that node will TX DTC messages and some others stuff to let us know if happy or not. Just need to feed it some crap, and see what it likes. Probably speaks OBDII also.

0x1E5 is only message I spotted it speaking on an 14 LML chassis from few weeks ago.

 

[TheBac]

I heard my name and CANbus?

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Project #4.

 

[1FastBrick]

@kidturbo are you saying you know for certain it won't work with the LBZ ECU?

Or is it that the LBZ ECU doesn't have that data because it didn't have the same sensors to monitor like the LML does. I am sure that stuff is all in the column on the LML chassis.

 

[kidturbo]

Reading the original post again, if the ESP work fine with just an LBZ ECM connected, then what is the job of the box? Replicate an LBZ ECM on CANbus?

 

[JoshH]

Reading the original post again, if the ESP work fine with just an LBZ ECM connected, then what is the job of the box? Replicate an LBZ ECM on CANbus?

I want to use the electronic rack in an LB7. I need something to replicate the signal for the rack to work since the LB7 doesn't have any CAN communication wires. It would actually have uses beyond the diesel world though.

 

[kidturbo]

I want to use the electronic rack in an LB7. I need something to replicate the signal for the rack to work since the LB7 doesn't have any CAN communication wires. It would actually have uses beyond the diesel world though.

Ok that makes sense. CAN replicator for an ESP unit.
Shouldn't be too hard of thing the wire up and test. Shoot me a msg and I'll send you something to try.