Ok here is what is going on. The "Service Ride Select" light is coming on at different times while driving. All the actuators are working fine. The weird thing is that if I take the car off the ground and cycle the FX3 system the light will go off. Any suggestions as to what is going on here? It is starting to annoy me a little; I have had the shocks out 4-5 times over the last few days attempting to sort it out. The car is an ‘89; mods to the suspension are larger bars and coilovers.

Daniel

 

I'm still learning the FX-3 ropes, but this is what I've discovered to date:

If you have a service manual, there is a section that explains how to retrieve any stored trouble codes from the SRS computer which is the first step in repairing the system plus there are troubleshooting charts that walk you through a logical repair procedure based on conditions observed or measured.

On the the early models, all digital dash C4s (which were made through 1989), plus any other mid-model year C4s that had a 12-pin ALDL connector, you ground pins A & B on the ALDL connector under the dash just to the right of the steering wheel and count the flashes on the SRS light to see if any trouble codes have been stored.

On all C4's with a 16 pin ALDL connector (except the 1996 model), you ground pin G and the trouble codes for the SRS computer will be displayed on the LCD screen that doubles as your trip odometer and speedometer.

The appropriate service manual describes exactly how to extract the codes for either system as well as explaining what the codes mean.

Without the computer codes, you are shooting in the dark if you try to troubleshoot a FX-3 problem but a couple possibilities are bad grounds or battery wires going to the dampening adjustment motors or bad ground/signal leads coming from the position sensors to the computer.

So, first you should check all connectors associated with each shock and make sure they are not corroded or dirty. Wiggle each of them in turn and see if the problem goes away. If it does, you have a bad connection to deal with.

Another possibility is the driver transistors in the SRS computer itself. If the computer commands the dampening motor to move but the driver transistors are bad or leaky, nothing will happen (or not enough will happen), the expected results will not be fed back by the position sensors, and the SRS trouble light will come on.

Changing the actuators or shocks will not correct this sort of failure, you must repair or replace the computer itself.

Lastly, if you install a High Energy Ignition and coincidentally begin to have problems with your Selective Ride System, the wiring from the HEI is cross talking into the SRS wiring.

Reroute the wires from the HEI so that it does not run parallel to any OEM wiring and try relocating the HEI control box to a different location to minimize the problem.

One final thought: like most electrical problems with a C4, check the connectors first and make sure they are free of corrosion and making good contact before you go on to more exotic solutions.

In the absence problems caused by a HEI system, poor connections and/or grounds are where most of the SRS problems originate.

Hope this helps!

 

I've a 95 so my plug setup is different. I believe you have to jump A to B on an 89. Use the search and look up "Pulling codes on an 89".
You didn't mention it but I'd first see if any codes have been tripped.

Here is a good post I saved from C4cruiser on what the codes mean.

"Error codes 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 moving 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 detent location"

Note:- The following instructions are for a later model than 89 but I left it in as it gives discription of pin layout if you aren't familiar with it. In an 89 I believe it is Pin A & B

"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."

Note:- The actuator builder mentioned is Captain Z http://www.captainzcnc.com/

"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."
Hope this is of some help to you.

 

Thanks for the great info. I found the problem to be the rear right actuator it was not sitting flush to the top of the shock due to a small peace of rubber where the clip snaps in to hold the actuator to the top of the shock (I am guessing from one of the old bushings). I hadn't caught it before, what had been happening is the actuator would fit flush until moved to the performance position then the movement would cause it to twist off the mount by about 2-3mm causing the code to be thrown. A stupid error I should have caught. Again, Thanks for the help

Daniel