First, I'm sure there will be a lot of head shaking after reading this and I understand. Hindsight is 20/20 and I now realize I did things in the incorrect order....just to get that out of the way.

I have a '99 car that came with the F45 option that is now a dedicated race car. Knowing of all the little VATS and associated issues that can crop up I chose to remove the bcm from the car, along with the ignition switch, and just have a "hot" switch and push-button start. ABS works fine and I've gotten around the TC/AH by pulling the Tq Delivered (PIN #5) wire from the red connector on the PCM. My issue now is that the car has decided that it wants to recognize that the mag shocks aren't present (did many events w/ out this issue as it's never had the f45 shocks as long as I've had it....event one full event after pulling the bcm), so it gives the shocks inoperative, max speed 80mph messages.

I know that the proper chronological order of this project should have been to use a tech 2 to disable the f45 option, THEN pull the bcm/ignition switch but now that I have, I can't use a tech 2 to disable (the tech 2 never recognizes that the ignition switch is "ON", for whatever reason).

All that to get to my question....where is this message in the DIC directly coming from? I've pulled the ESC, the harness to the EBCM (temporarily), the BCM is long gone and I've even swapped in a pcm from an 02 car that never knew anything about an f45 option....message persists. The cluster looking for it is one guess but another source has told me that all the clusters are the same. I've searched the forum and the internet and can't find a complete ESC wiring diagram to see what is going where....so that I can try to track down how the cluster knows that the mag shocks aren't there.

Again, I know it's not the typical scenario...and I know I've learned what NOT to do now but it is what it is. Any help would be greatly appreciated.

thanks,

Chris

 

I can provide the 99 schematics but you can't remove the RPO without a BCM. Maybe you can reprogram the PCM to ignore the ESC input and the signal sent to the serial bus which is connected to the IPC. All the IPCs are the same with the exception of where to put the Air Bag light and HUD compatibility.

Might just need to remove the ESC input to the PCM.

You should be able to raise the speed limit with a PCM reprogram. At least I know you can do it with the 2mph limit for a CL issue.


Mr. Sam

 

That was my suspicion since you have to go into the bcm area in with the tech 2 to disable. If you have a schematic detailing the pcm pins for the esc that would be great. All the ones I can find do not include a ref for esc or rtd.

I sincerely appreciate your time/input!!

 

Here are the schematics. I have more info if you need it but this should be what you need.

https://www.dropbox.com/sh/xnpwge9ik...islTnZ_3a?dl=0


Mr. Sam

 

Thank you!!!

 

I would have thought that the ESC module was unplugged and removed so a new PCM should have not activated and caused your issues.


Mr. Sam

 

That was my thinking as well. And, to be honest, I may have jumped the gun. I saw the "shocks inoperable" message and assumed the "max speed 80mph" was soon to follow. I went ahead and pulled pins 38 and 50 from the PCM based on the information you sent me (thanks again) just in an effort to break all ties between the pcm and the esc along with now only having EBTCM, PCM and IPC serial connections available via the star connector #2. I then re-flashed the PCM....just to be sure. The "shocks inoperable" still barks but after a few sessions on track this past weekend, no speed limitations.

Now on to intermittent ABS...but that's a different thread.

Can't thank you enough for your time!!!

 

Not sure what is going on but if you are happy then all is good.


Mr. Sam

 

I could easily believe that enabling/disabling the ESC sets some flag in the cluster to either check for it and display a message if it can't communicate with it or ignore it.

A member here tried the RCDLR (radio receiver) from a Z06 and could not get the TPMS programming. So, in that case it appeared the BCM programming turned-off the tire pressure monitor portion of the RCDLR module.