CAN BUS and Body Control Module Programing

I have spent several hours viewing many of HP Academy (HPA) training videos about ECU tuning, wiring, and CAN Bus, including several of The HPA earlier webinars on the subject of reprogramming modules. But none of the training videos have addressed my issues. I have also researched the HP Tuners devices and programs that HPA recommend and am getting close to making a decision about buying the VCM Suite. However, before I do that I want to HPA’s opinion as to whether or not the HP Tuners programs will help me reach my goals. Or, if there is another way to solve my issues. I have already purchased the GM Global Diagnostics 2, the GM Data Bus Diagnostic software, and the Bosch Multiple Diagnostic Interface 2, and have programmed a couple modules with the OEM factory programs.

My Project Car: I bought a salvaged 2017 SS Chevrolet Camaro 6.2L engine and 8 speed automatic transmission that I installed in a 1969 Camaro. Included with the engine and transmission were almost all of the control modules and the wiring harnesses from the same vehicle. I added some salvage-yard components and new parts, including the entire Gen 6 Camaro dash and center console, the HVAC system, Infotainment system, including the radio, phone, and navigation control modules, and amplifier. Every system is hooked up, the engine runs very well, and the dash appears to display everything that it should. I don't get any engine or transmission DTCs when scanned. Amazingly, all the other system components that I added are active but some of the features are not working correctly.

Description of Problems: When the start button is pressed to activate the electrical systems, and then after the engine starts, I get a lot of error messages and warning icons on the dash screen. And naturally I get numerous DTCs related to various subsystems when scanned. A large majority of the errors are related to the components of the Gen 6 Camaro electrical system that are not being used in this Build, including: the anti-lock brake unit, airbag system, collision detection system, electric parking brake, brake fluid level sensor, fuel pumps, fuel pump controller and other things.

Q1: Does the HP Tuners software allow me to cause the body control module and other systems ignore the fact that some of the system components are not used? Can calibration parameter changes be used to cause those systems to ignore unused devices?

Q2: Many of the devices that are not used are connected to the CAN BUS. Can those devices be removed from the BUS by simply cutting the wires, or by adding a device jumper wire that mimics an “ok” status?

Goals:

1) Eliminate all of the DTCs and dash error messages for the parts of the Gen 6 Camaro systems that are not used or needed.

2) Be able to remove the unused Gen 6 Camaro devices and some of the wiring that is not being used.

3) Be able to program the ECU input and output signals to control aftermarket cooling fans, fuel level sensor, fuel pumps, AC compressor, wiper motor, etc.

I would appreciate any advice on the issues I have described. Thank you.

q1 : Hptuners disabling bcm features or status messages. Not to my knowledge but I'm not the most experienced with the platform or Hptuners.

q2 : no, eliminating a node will not disable the system or messages.

the viable way to eliminate all of the status messages and such is by mimicking the message output on the network that will keep the rest of the devices happy. this is usually a very time consuming process that requires a lot of time testing messages from a known good reference. if the device is bidirectional in a communication model (think about it like a closed loop setup over CAN), it'll take even longer to characterize.

Hi Dean,

No, I don't believe you'll be able to eliminate the status messages and DTC's using HPT sorry.

For your second question Mitch has nailed it. This is a big job sadly and there are likely to be multiple messages from each unit you'll need to replicate.

You won't be able to 'program' the ECU inputs/outputs as such to do what you're wanting unfortunately. You should be able to swap out individual outputs like fans and fuel pumps particularly given the gen 6 is a traditional fuel pump (not brushless). The reality is that anything is possible but some things are just going to be very difficult and/or expensive so hence may not make sense to do.

Andre and Mitch,

Thanks for the replies. Despite the fact that wanting to achieve my goals will be time consuming and expensive, I am not ready to give up yet. My project car is a retirement hobby and I have ample time to work through troubleshooting and an ample budget for software and parts. Even if I cannot eliminate all the DSCs, if I can drive the car and get correct gauge information on the dash screen, I will be happy. I already got the fuel cell fuel pumps to work using relays and a trigger signal from the harness.

Mitch,

You stated that "the viable way to eliminate all of the status messages and such is by mimicking the message output on the network that will keep the rest of the devices happy."

What devices and software will allow me to do that investigation and connect to the CAN BUS and provide message mimicking?

I have been getting a lot of feeds on Facebook from a company Inpronic USA that is selling a CAN-BUS Multiplex Trainer and Sniffer Tool. Its advertisement says it can test and operate CAN connected devices in order to isolate signals. Do you have any experience with those kind of products?

i wouldn't recommend anything other than the peak pcan (or peak pcan fd) to a newcomer.

peak 's usb hardware is supported by more software solutions than anything else on the market that I'm aware of.

pcan viewer - free ,

pcan explorer - charge for but fairly powerful.

savvycan - supported + free

Linux socketcan - natively supported + free

ecumaster can comms - supported

python-can - supported and free.

busmaster - supported and free

Thanks so much for spending your time to provide the advice. I will try the Peak PCAN route. I went to the Peak website and looked at all the PCAN devices and software options; it was impressive and also difficult to determine what I need to buy.

I made some screenshots (attached) of the products that I think I need -- Peak OBD-2 Diagnostics Cable, Peak PCAN USB Cable, Peak PCAN View Software (free), Peak PCAN-OBD-2 Viewer Software (free), and Peak PCAN Explorer 6 Software.

Do you think that is a good start to help me achieve my goal of being able to modify the PID input and output messages on the CAN Bus?

Thanks again for your input.

I believe you're incorrectly using the phrase 'PID input anf output messages' incorrectly and are actually referring to just CAN messages that keep the controllers happy. the phrase 'PID' is commonly used when referring to obd2 or UDS style communications when requesting or receiving some block of information that scantools request typically using CAN for their communication model.

start with a peak pcan usb fd and the appropriate connection cable. you've got a long ways to go and step 1 is just getting messages comfortable with understanding the patterns you'll see and understanding how the data looks. from there, you'll need to just get a baseline of what your system has, which ID's are observed, how frequently they're sent on the canbus, etc. and at some point, you'll need a known good reference vehicle for sniffing also to understand what messages are being presented, and compare the 2.

this is not light work, and will require some pretty adequate knowledge and understanding of CAN systems and usually a little bit of luck as well.

Thanks for the advice.