arc system messed up

scbird1

Registered User
I know I know most would like to kill this thing anyway but I would like to keep the stock features working. I looked at most of the things that can go wrong. I swopped out both relays,computer and took all the actuaters off the shocks. They all work but the firm ride light still blinks 4 times and there is is a lot of clicking going on. It works for about the first 4 stops on auto mode but still clicks like 8 times or so and then it starts the lite to blink 4 times and still dose all that clicking on firm ride actuation. Only one click when it goes back to nomal ride. The shocks are fine as far as I can tell. The little blade thing moves freely in all. what if some one messed with the shocks and turned the blade thing 180 % off? Its a 94 by the way and I disconnected the wire {one at a time} to each actuator with only a change in the # of firm light blinks. :confused:
 
1 flash = Driver side rear
2 flashes = Passenger side rear
3 flashes = Passenger side front
4 flashes = Driver side front


Make sure the front driver's shock pin can rotate smoothly with little effort. Lube it with WD-40 or something. If that doesn't help, then try swapping the actuator from the drivers to the passenger side and see if the flashes change.

Either the shock is bad, the actuator is bad, or the wires for the actuator are bad.
 
I'm in similar predicament. My 94 has been having ARC problems for a while. I went through the actuators and found one bad one, but that still didn't solve the problem. Also found a short in the circuit board located behind the dash panel where the "FIRM" light blinks. Switched out the circuit board, still the problem exists. Tried changing out the computer and the relays in the trunk...no joy there either. I'm going to try going through the actuators again and if I can't solve it then I may end up taking to Ford as last resort. I'm not sure about my shocks. My front ones have been replaced, but rear are still original with about 100,000 miles.
 
What would cause the relays to click like 8 times with all intact and then with all actuaters off shocks but still connected and then with all actuaters unpluged one at a time till they were all unpluged. My only guess is that one of the sensors that activte the system is fried. Brake or vac switch or steering. All these will cause the firm ride to ativate. Is there any more im missing?
There is a diagnostics plug on this thing. Who or what can be used to check the system out. Other than FORD. I cant afford that.
 
scbird1; I have had almost the same problem since purchasing the car. Prior to this point, I had not seen anyone else with a similar ARC situation.

I tried most of what you did, including checking all 4 shocks and actuators, switching actuators, switching the relays, checking for proper activation from the various sensors, ect. I opened and inspected the computer, it appeared flawless. I checked for a loose connection at the computer, it was fine. I checked the wiring for shorts which was visible to me, it was fine.

It does nearly what you describe. In automatic mode, it clicks then blinks three times whenever hard acceleration, hard braking, hard turning, or over 90 occur. If nothing is occuring to switch it from soft to firm while in auto mode, it simply blinks continously in increments of three. Switching to firm is all that alleviates the problem, no difference in ride can be detected. My shocks are stock units, age unknown.

I thought about changing the computer, but assumed it would be a waste of time and money.

The only other possibility which seems logical now is that a short exists somewhere in the wiring which is hidden out of view; I simply can not think of anything else. Perhaps there is more to this system than anyone is aware, and these parts are out of view.

I also originally wanted to keep the ARC system like you. However, with the diagnostic trouble I have encountered trying to fix the problem, and due to the fact that the replacement Tokico Illumna II shocks are both inferior to and significantly more expensive than aftermarket alternatives, I think I might eliminate the system anyway.
 
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keep in mind there is a steering wheel position sensor that has an input into the suspension control system. If there is a harness to have possible issues, that is one i'd want to take a look at.

Have you ever pulled the codes from the suspension system? It has a connector the same as the ECM for pulling codes.

At least for the 89, Alldata DIY has 40 or so pinpoint tests to track down issues with the system based on any codes from the system.
 
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