Is there someone in the SF Bay area with a TECH II that can deactivate the F45 option on my 99 coupe. All the stealerships are clueless.

 

I work for a dealership in Fairfield (about 45 min east of S.F.). I can get one of my techs to try it for you. The F45 is a function of the BCM and after 50 ignition cycles some parts of the BCM can not be programmed out of it. If you can get your car up here we will try for free. Worst case is that you may need a new BCM that can be programmed. Let me know if this will work.

 

PM sent

 

I thought on the 99 we had to use sims as we could not delete them from the computer. If your successful please post as I am going with Bilstens later this year on my 99 F45 setup

 

I'm not sure about your '99 but I was able to delete F45 in my '01 only after unplugging the wiring harnesses in the little compartment on the left side in the hatchback area.

 

I'm going up to Fairfield in a week or two and see if Rich can de-program mine using a Tech 2. In the meantime I was experimenting with the 15 ohm resistor solution. I got the plug going to the shock spoofed, but I ran into a problem with the shock position sensor plug having 3 pins instead of 2 like the shock. According to the manual, the pinout is:
A = gnd
B = sensor output to your ESC
C = DC power
pins are referenced with A on the right-most side as you look at the plug on your car with snaplock on top. I put a 15 ohm resistor between B and C. It didn't work and of course I'm getting 1760 and 1761 error codes now. Does anyone know for sure how to wire these? Do I need two 15 ohm resistors - one between A and B and one between B and C? The shock position sensor appears to be an electronic voltage divider and I can't use an ohmmeter to reverse engineer it. Any help would be much appreciated.
Thanks!
John

 

Hey John,
I'll be taking Rich up on his offer next week so I'll post results on how the deprograming works out. For now I'm gonna crack open the shop manuals tomorrow and fool around with the resistor scheme. There was some prity helpful stuff in the CF archives. Check it out.

http://forums.corvetteforum.com/show...um_id=1&arch=1

If I get somthing figured out I'll let you know.
Good luck,
Dave

 

Almost forgot. A big thanks to Rich @ Woodard for offering his services.

 

[Hi there,
The mod of choice would be an F55 magnetic retrofit.
12499507 is the part number. and they are $1900 on the web for the 4 shocks and the control module.
If they are installed at a GM dealership, they may be a bit more, but carry a lifetime warranty.
You can use 04 ZO6 shocks, but you will have to reformat the RPO configuration for your car, which is not easy to do.
Allthebest, c4c5]

This is the reply I got from another forum concerning the same F45 dilema, I have a 98 and was inquiring about what shocks other then the F45 replacements can be used.

 

Hey Dave...let me know when you're going and possibly I could meet up with you in Fairfield. Where are you driving from?

I read those threads...I can't imagine using really high wattage resistors as mentioned. Also I'm not sure about the comment saying don't switch to performance or will burn up the resistor...I'll be working on this tomorrow as well because I couldn't wait to get my Bilsteins on. Just did the front so far and it feels much better already. I bet when we get Bilsteins on all for corners, we'll wonder how GM could ever put this RTD system on our cars and why we waited as long as we did to change them out.
John

 

You have to remove the rear ride control computer in the drivers side rear compartment then remove the option with the tech 2 and then reset the computer by removing the PCM fuse's.

I had the same problem once I reset the computer F45 was gone this was on a 97 coupe

 

John,
Depending on work I will try to get up to Fairfield on Monday or Tuesday morning that way I can just go into work late. I'll be leaving from Montara which is about 5 miles south of Pacifica.

As for fooling the system I think mfrnka deduction for correct resistor wattage is right on. I have both 25W 10 & 15 ohm resistors which are encased in a mountable heat sink. I know the wattage is low but they are way under rated at 25W. My thinking is I'll mount them on a pice of 3/8 or 1/4 inch aluminium plate (Further heat sinking) and wire them right to the ESC module in the rear compartment so there isn't all that stuff in the wheel well.
The shop manual gives the the position sensor power supply voltage @ 8V with the sensor normal operating range of 0.35V-4.75V. In the sensor diagnostics section of the manual for DTC C1763 (RR postion sensor) one step is to place a jumper between termals A and B on conector C404, that would be the sensor terminal. The voltage should then read between 4.0 - 5.5V on the scan tool monitoring the sensor voltage. I'll be trying that out today. I'll update later on how this works out.

Dave

 

My origanal plan for connecting resistors to the ESC module was a bit more involed then what I wanted to do. I wound up cutting off the plug on the F45 shocks right at the mounting gromet then spliced in the 15 ohm 25W resistor and mounted them to the frame and just left the posistion sensor connected. So far its worked with no problems (no codes), I can set the ride control switch to any posistion and not burn up the resistors. Man what a difference in handling, Its like a hole new car.
I'm still planing on taking Rick up on his offer to try and remove the F45 option from the BCM, probably next week But at least for now I can drive faster then 80mph



The pic. just shows the resistor and where I mounted them..

 

I did the very same thing. I can't believe the difference in the car. The F45 shocks from the rear of the car seemed like they hardly rebound when compressed. Now I wonder how long they've been like that? I too left the F45 position sensors in place and plan to get the F45 option removed from the BCM.

Now I have my next project in mind. Once I get the F45 option removed, I'm thinking to leave the RTD computer in place and reverse engineer it so possibly I could use the 4 position sensor outputs to log how my suspension is actually working on a particular track. I would need to calibrate position sensor outputs of course. I wonder if anyone else has actually tried this? I got this idea talking to LEAFTYE a few days ago.
Cheers
John

 

Thank goodness you got rid of that nasty F45...