My light is coming on to service ride control. Do you have to take metal work off the rear wheel well to get at rear shocks? Is there a way to tell which one is acting up?

 

You should be able to read the codes from the service light. On my 89 I ground terminal "B" on the ALDL but on your 90 I don't know if its the same.

Get the shop manual for the how to access and troubleshooting of the codes you receive. (unless someone with your year chimes in :D )

 

For the 90, you ground A-C terminals

12 = Start of sequence
13 = Left rear time out
14 = Right Front time out
21 = Left Front time out
22 = Right Rear time out
31 = Left Front out of position
32 = Right Front out of position
33 = Left Rear out of position
34 = Right Rear out of position


Out of position codes are triggered if the computer senses that the actuator has not found the end stop position on the shock. Remove actuator at the indicated shock. Turn the valve gear on the shock stops after about 3 / 4 of turn, then you have a bad actuator. If it spins around continuously then it is a bad shock
41 = Selective ride control switch short to voltage
42 = Selective ride control switch open contacts

You can have a code 42 if you leave the switch in between indented positions

43 = selective ride control switch circuit open.

Oh and if you need replacement parts, there are two different sets of FX3 gear 89-91 and 92-95. They are not interchangeable


Email me if you have any questions as I just got my shocks back from being revalved at Bilstein.

Forgot to add, to access the rear shocks, just jack up the rear of the car, and unbolt the shock from the lower knuckle first, then undo the top two bolts holding it in at the frame. It's around ten minutes to do.


[Modified by Jeffvette, 12:52 AM 3/15/2002]

 

Finally, someone who understands the ride control feature. I have 96 CE LT4 with it. Here's my question...with the ASR disengaged, I've experienced several instances of the throttle backing off when the rear end got loose in a hard accelerating (as in spinning the tires) turn.
Is that the real time dampening system functioning, or an unrelated loss of power? I was not under the impression that the real time damping system interacts with the engine controls. Any treatise you can offer on it's operation would really be appreciated. The owners manual isn't worth squat in explaining it's operation. Thanks for any replies. Cire96 :confused:

 

If you hammer the throttle with or without the ASR system engage, the FX3 system will make adjustments as programmed.

The 1996 is the first year for the Real Time Damping (F45) system. Although closely related to the FX3, it uses different shocks and software. Each shock on the F45 is controlled independently while the FX3 system does not. The F45 shocks are manufactured by Delphi Automotive while the FX3 is Bilstein. The FX3 shocks are rebuildable while the F45 are not (or so claimed).

I would love to get additional information on the F45 system and how to access the ECM tables to make changes. I feel the F45 is very subtle in its operation and could stand to be more aggressive. I suspect its the prime reason why my car rides so well at high speeds traveling in west Texas yet maintains excellent control. The F45 springs on the 1996 Corvette are the softest of all the C4 yet it remains somewhat high-performance if you use the middle or firm settings. I normally use the middle setting since I find the soft setting too soft for nomal street driving.

 

Mez: Thanks for the information on the F45 system used in my CE. The lingering question is whether or not the system has any connection to the throttle control cable unit (as does the ASR system).
If not, is it possible that the ASR takes a few seconds to disengage? In each of the instances where I've noted the throttle glitch, I'd just toggled off the ASR. I agree with your choice of settings. I keep mine on the sport or competition setting.Cire96

 

The ASR does not use the selective ride control in any of it's corrections. The ASR has that glitch to insure that everything is ok, so hence the hesitation.

 

Jeff is correct. The throttle cable and FX3 are not directly connected. It is my understanding that the F45 make changes to the shock settings with speed, road and car dynamics change. Like I said, I would love to see more specific information on the F45/FX3 to better understand what it is doing under various conditions. In my search, I have only found an article fron Hal H.

The ASR is a little slow in its cycle so that is perhaps what you are feeling in your 1996 F45 system.



[Modified by Mez, 5:53 PM 3/15/2002]

 

I've experienced a similar glitch when making a hard accelerating turn. I
asked the same question on the Forum befor and was told that if you have
less then a 1/2 tank of gas it is possible the fuel pump sucks air. I was
told it is a design flaw.

However, that being said, if you have the ASR off and you accelerate hard
and come close to redline then you will get pedal pushback and the timing
is retarded.