I have a '94 and I have to replace a sensor on the car. Yeah, that is specific!

The sensor is related to the shocks on the car. I don't think that the sensors are directly on the shocks, as I have already replaced those, but the sensor has something to do with the suspension on the car.

Yes, I am one of those with the FX-3 selective ride.

I know that it is not well liked in the C4 world.

Anybody have any experience dealing with a "sensor" pertaining to the suspension on the car? Anybody know if it is an easy fix or will I have to resort to the manglers at Chevrolet?

I know that this is a pretty ambiguous post, but any light that could be shed on this opaque matter would be great!

 

They are called actuators, not sensors, and are mounted directly on top of each shock. They perform a check each time the key is turned on and then go to the setting you have selected. If one of them is not working correctly you shoud have a warning light on the dash. The actuators are expensive, so are the FX3 shocks. There is a diagnostic procedure, which I don't have hand, to tell you which wheel position is bad.

 

Thanks for the input.

My error about calling them a "sensor".

Chevrolet diagnosed that they are bad on the front left and right rear.

Is the change pretty easy?

 

Changing the actuator is very easy on the front and takes about 2 minutes. On the rear you have to take the shock off to get to it, but still easy and quick, maybe 15 minutes. Parts on the other hand are expensive. Usually it is the little gear on the shock that breaks, not the actuator, so be sure you aren't buying parts you don't need. Shocks run about $180 each new, new actuators are over $300 each if I remember correctly. If the warning light is on there is no need to panic, the shocks still work and will go to the default setting automatically. I believe default is the sport setting, but again I am not sure. Car is safe and you won't hurt anything, nor will it hurt you, to keep driving it until you are sure what you need to do.

 

Error cosdes will be set for the SRC and the codes will tell you which corner is involved and whether or not the problem is the shock or the actuator.

SRC codes are:
13 - Left Rear Time Out
14 - Right Front Time Out
21 - Left Front Time Out
22 - Right Rear Time Out

These codes are stored if the actuators are movbing too slowly or not receiving the proper feedback signal

31 - Left Front out of position
32 - Right Front out of position
33 - Left Rear out of position
34 - Right Rear out of position

These codes are stored if the actuator does not find the end stop position on the shock rod. This is usually a broken gear on the shock rod and are the most common error codes.

Other codes:
23 - Loss of vehicle speed signal
This code appears when the ignition switch is cycled on/off 3 times without the vehicle moving. The SRC light on the DIC should go off after the car is driven. The code remains in history until cleared.

41 - SRC switch short to voltage
42 - SRC switch open contacts
Code 42 usually results in the console switch not being in the proper dentent location


To pull the codes, use a paper clip to jumper pins A (ground) and C (SRC) in the ALDL and turn the ignition switch to ON but do not start the motor. Looking at the ALDL, Pin A is the right-most one on the upper level and Pin C is the second one to the left from A.

The SRC light will begin to flash. All code sequences start and end with a Code 12 and each code is repeated 3 times before the next code number is displayed. There is a one second pause between each of the three repeated codes and a three second pause between each new code.

So a Code 12 is blink - blink blink and repeats twice more. A code 32 is blink blink blink - blink blink. After the second series of Code 12 (to denote the end of the SRC error codes, the entire cycle repeats until you either turn the ignition off or pull the jumper.

You can remove the actuator from the front shocks by simply pulling the C-clip from the bottom of the actuator. Pull straight up to remove it. There is a small pot-metal gear on the top of the shock rod. Most problems with FX3 is this gear breaking.

Bilstein will rebuild the shocks for around $100. The gear is not available from GM or by itself from Bilstein. Bilstein can also provide custom valving for the shocks if you want.

You can contact Bilstein in Poway, CA (near San Diego) at 1-800-537-1085. Ask for Jack French or Bill Hindorf. They are the FX3 gurus at Bilstein.

The actuators are pricey but there is (was?) a CF member who was replacing the internal plastic righ gear with a billet aluminum piece. Sources for replacement actuators might be eBay or IIRC, Bilstein may even carry them.

The SRC Controller is located in the compartment behind the driver's seat. A couple of years ago, Doug Rippie Motorsports had a controller available that featured a replacable chip that allowed for even finer tuning of the shocks. The chip could be burned for specific applications like autocross or road racing.

That, along with custom shock valving from Bilstein makes FX3 a great supsension system for those that want to spend the money.

 

Thanks guys, for all your great input!

As Jeff Gordon would say, "You guys are AWESOME!"

 

You can have the Shocks rebuilt by Bilstein....I had a gear broken on the shock and the gear in the actuator was broke as well. To have the shock rebuilt was $140 ($100 for the rebuild and $40 for the new shaft as it is part that has the gear on it). The guy is CaptainZ CNC that rebuilds the actuator for $100, worked for me. $240 and I was back in business.

 

I am not getting any error codes from my ECM, but the Service Ride Control Light does not illuminate in test mode when I first turn on the ignition.

Does this mean my bulb is simply burned out and my FX-3 actuators are still working?

 

You should be able to easily determine if they are working with a tool the good Lord gave you...your butt. The settings are different enough that it's easy to feel if they are working.

It's possible that the bulb was removed by a prior owner if/when the system didn't work for them.

 

I got my rear Bilsteins from eshocks.com...$170 each...best price I have found yet! Others were north of $40-50 per shock more!
The actuators are held on the top of the shock by a triangular spring clip..real easy to change after taking the bolts out of the shock brackets! Make sure to open your doors, hood and rear hatch before jacking it up so you don't tweak a body panel!

 

I can hear the actuator servos when when I first turn the ignition. When I pull the DIC to remove my Bose head unit, I'll inspect the bulb then. When I first got the car, I could feel a slight difference, but nothing to write home about. I keep it on Sport mode all the time, anyhow. Thanks for the 411.

 

Here's some additional info.....

http://www.captainzcnc.com/

 

good luck