BCM and slip ring

[slipknot09]

I definitely will document it so others can follow it through to a solution in the future.

So I went back in with the Tech 2 to play around and it won't let me access the BCM now. It recognises it is from the wrong model. I thought the BCMs were interchangeable (at build level) between VY and VZ.

I can operate all the functions, less start the car, so it is working.

Thoughts or experience with this anyone?

Cheers n Beers
Jolls

Yes all the bcms have the same pinout and all speak the same language. Just some functions may not operate correctly and good chance of a DTC if for example a wagon one was used in a sedan. I’ve also seen people on this site mention that certain bcms require certain airbag modules but I have no experience with that but believe the people that mentioned it.
Also a HI BCM would be expecting data from things like a memory seat module or rear seat entertainment stuff

 

[Lex]

Yes all the bcms have the same pinout and all speak the same language. Just some functions may not operate correctly and good chance of a DTC if for example a wagon one was used in a sedan. I’ve also seen people on this site mention that certain bcms require certain airbag modules but I have no experience with that but believe the people that mentioned it.
Also a HI BCM would be expecting data from things like a memory seat module or rear seat entertainment stuff

I thought that was ecm?
Another member (@vombil?) was having trouble with his ute & swapped something, which l think was the ecm?

I'm probably wrong?

 

[Jolls]

Hi Lex
The terms get used poorly and can change across brands and types. The way it has been explained to me is that in the early computer days ECM was the term used as it controlled the engine. There are some basic cars that would still have an ECM only. Then there are modules that interact with other elements of the system including the transmission. So they become Powertrain Management Modules and have developed from there to include body, chassis, ABS and other control modules.

So it could well be that the other member was referring to the ECU as the correct term in an earlier model or referring to the PCM from a later model.

The key modules in the VY are BCM, ABS, PIM, PCM and SRS then add climate control, instrument, and radio
The key modules in the VZ are the same plus throttle actuator control and accelerator pedal position modules for the drive by wire system.

The powertrain interface module is required int he VY/VZ because the the GM PCM system is a 7 to 0v system at one frequency and the rest of the serial communications in the models are 0 to 5V at a different frequency.

They just like to make it interesting!

In my case the PIM is receiving the correct code from the BCM. So it enables the starter relay to crank the engine. The PCM is then sent the code from the PIM - if that doesn't match the PCM's code the PCM shuts down the fuel, ignition and comms signals as part of the anti theft system. So that is what I am trying to get around. The resolution appeared to be simply re-linking the BCM and PIM/PCM (which in theory I have now done using the VZ PIM. But I suspect I am still getting a no start signal from the PCM.

The previous owner tells me it ran like a dream until he stuffed the transmission and the only thang that has changed is OZTrack changing the BCM to a manual configuration. So if I can't sort it over the next few days @slipknot09 is right in that I will need to get the VATs deleted in the PCM so it isn't an issue.

A bit more time and a bit more pain - but we will get there eventually.

Cheers n Beers
Jolls

 

[slipknot09]

Sorry if I’m confused but if your running an ls1 pcm removing vats is simple and only a 10 min job. I use an AVT cable/box but pcmhammer has been updated to support OBDLink obd dongles. Just use tunerpro to edit bin and remove VATS. Disregard this message if I’ve gotten confused, if you need help with how to use pcmhammer and tunerpro you’re welcome to ask. If you need files I can supply them also

 

[slipknot09]

Also I believe the difference with Engine Control Module (ECM) and Powertrain Control Module (PCM) is the ECM just controls engine functions and not transmission stuff. Probably makes it easier for models to have different drivetrains like how the VZ had so many different combinations. They had at least 3 V8’s and 2 V6’s (maybe more?).
ECU’s are just Electronic Control Units and can be used in dozens or even 100’s of things in cars. These days are referred to as modules. That’s just my understanding of things and please correct me if I’m wrong

 

[Jolls]

I have, according to the Tech 2, achieved successful linking of the BCM and the PIM/PCM.

The engine cranks so the BCM is communicating with the PIM. The and get the same fault I had with the VY BCM P1626 Theft Deterrent System, Fuel System Enable Circuit. So there is something going wrong between the PIM and PCM.

I may have a line on a VY BCM/PIM and key fob that I can borrow so will work that to see if we get a positive result. I am not positive but it is worth a shot. It could also be the PCM so I will research in the background re VATS delete.

I am concerned that the PCM is the problem - may be easier to simply purchase a PCM form LSXtreme and be done with it!

Cheers n Beers
Jolls

 

[Lex]

I have, according to the Tech 2, achieved successful linking of the BCM and the PIM/PCM.

The engine cranks so the BCM is communicating with the PIM. The and get the same fault I had with the VY BCM P1626 Theft Deterrent System, Fuel System Enable Circuit. So there is something going wrong between the PIM and PCM.

I may have a line on a VY BCM/PIM and key fob that I can borrow so will work that to see if we get a positive result. I am not positive but it is worth a shot. It could also be the PCM so I will research in the background re VATS delete.

I am concerned that the PCM is the problem - may be easier to simply purchase a PCM form LSXtreme and be done with it!

Cheers n Beers
Jolls

Does it lock unlock with the fob?

When l've been playing with the key ring, or barrel or whatever. Sometimes when l've reassembled it. I go to start the car & wont start, as in can't move the key. Move key ring assemble a touch & then l can move the key & start it. Other times it just wont start. I sit in the seat , take key out, lock with the fob, unlock it put the key back in & it will start.

My car is certainly not your car, but sometimes these fixes are fast & easy, & don't cost anything.

Good luck with it. I know you will sort sooner or later? Better sooner, eh.

 

[Jolls]

Yes,

Now that I have changed the BCM I can open it with the fob. The key is recognised by the BCM and the PIM enables the starter circuit. So that part of it is all good. The problem I have is definitely something to do with the VATs side of the house in the PCM. I can actuate all of the functions through the PCM using the Tech 2 so deleting the VATS may be the easiest to do. I will call OzTrack tomorrow and have a chat with them to see if they have records for what they have done. Maybe I can send it back to them as it was supposedly working fine before they changed if from auto to manual.

Just speculating now really - I will let you know how I get on. Should have the Vident tomorrow "touch wood". I doubt it will change much given I have confirmed programming success with the Tech 2.

Cheers n Beers
Jolls

 

[Lex]

Yes,

Now that I have changed the BCM I can open it with the fob. The key is recognised by the BCM and the PIM enables the starter circuit. So that part of it is all good. The problem I have is definitely something to do with the VATs side of the house in the PCM. I can actuate all of the functions through the PCM using the Tech 2 so deleting the VATS may be the easiest to do. I will call OzTrack tomorrow and have a chat with them to see if they have records for what they have done. Maybe I can send it back to them as it was supposedly working fine before they changed if from auto to manual.

Just speculating now really - I will let you know how I get on. Should have the Vident tomorrow "touch wood". I doubt it will change much given I have confirmed programming success with the Tech 2.

Cheers n Beers
Jolls

Have you sat in the car lock unlock with fob, try & start car?

 

[Jolls]

Lex,

Yes mate, tried that. Will give it another crack if I can hold of a VY BCM/key programmed for the original VY BCM.

Cheers n Beers
Jolls