I am getting ready to push this car off a cliff....

I have disconnected the RTD portion of the module in the rear of the car (leftmost of the 3 connectors on the large module. One of the others is TCS, not sure what the 3rd is.) and disabled RPO F45. RTD doesn't show in the onboard diagnostic anymore. The car shows no DTC codes. None. However, I get the dreaded "Maximum Speed 80MPH". The tech has been through every module with the Tech II looking for anything, and it looks clean.

I'd really like some sort of help on this, I'm completely stumped.

 

This may be the answer to your problem.

http://forums.corvetteforum.com/show....php?t=2060919

 

That says how to diagnose problems with the RTD. I've removed the RTD, along with the RPO code from the BCM.

There are a lot of people who have upgraded the shocks in their F45 and F55 equipped cars and been able to get by this. I'd really like to know if anyone else has seen this? Where is it getting the "Maximum Speed 80MPH" from, when the RTD is gone entirely? Where is it storing this information so it can be removed? It's not showing any DTC codes...

 

I told you in another thread you need to DISCONNECT the RTD module, from your description you have only disconnected one of the three connectors to the module.

DISCONNECT THE MODULE

TCS is managed by the EBCM located in the engine compartment, the unit in your trunk does NOTHING other than manage the F45 suspension ..... DISCONNECT IT ...... PLEASE .............

At this point you may have the car completely confused .... you may have to re-install the RPO and module ... get everything back in synch, then COMPLETELY disconnect the module and delete the RPO from the BCM.

 

WAIT WAIT WAIT ..........

In your original post on this you said you have the F55 suspension ..........

http://forums.corvetteforum.com/show....php?t=2058913

which is only available in a 2003 or 2004 vehicle .......

Now you're saying you have a car with the F45 suspension .....

You cannot delete the F45 from a car earlier than a 2001 ........ as I asked you in that original thread ... what year car do you have ?????

 

It's F55 in the RPO sheet in the glovebox, (Car is a 2004). Shows up as F45 in the BCM. The module is different. In the earlier cars, it's one small module. Mine is gigantic, and when you disconnect all three connectors, it comes back with a TCS communication failure. I had it completely disconnected, but that's what we found. When reconnecting all but the leftmost plug, the TCS comes back online.

 

Here's a pic of the module.

 

Nothing in the schematics that Bill Curlee posted shows a TCS connection .... nor is there anything in the F45 system either. Only wire between the F45 and the EBCM is the EBCM (which runs the TCS software) reports the output from the Steering Wheel Position Sensor to the ECS (Electronic Suspension Controller). Disconnecting that makes no difference in the F45 system.

What specific error was being reported when you pulled the cables off the ECS ???? was it a DTC, or were you using the DIC and it was reporting NO COMM with the TCS module ???? I'll PM Bill Curlee and have him look in his F55 specific manual at the wires that the connectors carry to the ESC ..... makes no sense to me why the loss of the ESC should affect the EBCM .... worst case if the EBCM was receiving data from the ESC you'd expect a DTC ... if the EBCM noticed the ESC was gone (not sending SOH messages) then you'd expect a Uxxxx "loss of comms" message ... which is no big deal. Modules post Uxxxx messages all the time.

Let me know EXACTLY what error message you were seeing .... I'll PM Bill to get more data .....

 

I was seeing TCS no Comm message with all three plugs disconnected, but no DTC. RTD No Comm disappeared when we deleted the RPO code. I used my super-scientific method of reconnecting all of the plugs that *don't* look like the standard plug used in the F45 system. That fixed the TCS No Comm message. F45 is still gone from the BCM. I wonder if it's disabling RTD on an F55 system through the BCM doesn't work?

The dealer I bought it from had put emulators on the shock plugs, but they aren't working for the right side of the car which is what brought me to this point.

 

You seem to have a lot of knowledge, but your statement above is incorrect. I have a 98 with F45 suspension which I completely removed including the RTD module and deleted the F45 option with a Tech II tool years ago without any issues.

 

You're correct .... I had a "senior moment" there (damn they're happening more and more often) .... I was thinking of the Tire Pressure Monitor System .... that can only be deleted on 2001 and up .....

Thanks for the correction.

 

Yup, now I agree.

 

Hmmmmm .... I'm wondering here .... but the F55 was "pulled forward" into the C5 .... it was originally planned for the C6 introduction .....

In the C6 the data network is wired differently. For example if you unplug all the connectors off the OnStar module, that drops (if I recall correctly) the BCM off the network and the car won't start.

I'm wondering if that's what's going on here ...... disconnecting the ESC is dropping the EBCM off the network. When Bill comes on we can check the wires coming in/out of the ESC .... then all you need to do is connect the two network wires together and you should be back in business ......

I sent Bill a PM ... we'll see him on here soon I suspect.

 

So, I was thinking about this a little more, and my thought for a possible temporary solution would be to remove the shock emulators and ohm each of them out to make sure they are all good, then clean/repair the terminals, plug the ESC back in and see if it will at least work until I can get the thing turned off properly and permanently. It's only throwing codes on the right side of the car when the ESC is connected, so there's a possibility that may work.

 

So, I took some of the emulators off of the rear to measure resistance. I found that the left side (where there are no error codes) measure 13ohms of resistance. The right side (where it throws codes) measure 24ohms of resistance. The right side emulator is noticably more burned than the left, to the point of bubbling plastic. The left side is obviously heating up.

 

Any word back from Bill? The dealership is sending me out a new set of emulators, but I'd like to fix the problem right, and for good!

 

ttt

 

No word back from Bill ... but I know he has an upcoming vacation .... he may well be on it now ..... since he hasn't posted any messages in the last few days ... I'm betting he's on that vacation.

The new emulators should hold you over, but I agree that a more permanent solution would be best.

We'll keep working on this

 

New emulators are on the way.

In the meantime, I spoke with Regis from Corvette Specialists in Riverside, who said that he can do the job, but it will require reprogramming three different modules because of the way they are integrated on the F55 system. He told me he'd done one before, and it was a pretty involved job. Currently, I have an appointment to drop the car off next wednesday and let him have at it. It's expensive, but if he can do it, well worth it.

 

"involved job"

this dealer guy is getting ready to RAPE U!!!!

playing with a TECH 2 is involved and expensive?

i undid my F45 at the dealer and it took 5 min and they DIDNOT charge me a penny..... yes it was free....