Shock Damping Control (ARC) Operation/Testing "How-To"

System Operation

The shock damping control feature, provides the selection of either a firm (sport) suspension tuning or an automatic ride control. Also included is the electronic variable orifice (EVO) steering control electronics.

This article contains general hardware diagnostics for the power steering control valve actuator and shock absorber electronic system control.

The system is activated using the ride select switch mounted on the center console to the right of the driver's seat.

With the ride select switch in the FIRM position, the shock absorber electronic system control adjusts shock absorber damping to provide a firm (sport) suspension tuning.

With the ride select switch in the AUTO position, the shock absorber electronic system control adjusts shock absorber damping to provide a soft ride during normal driving conditions. The shock absorber electronic system control changes suspension tuning to firm during hard braking, hard acceleration, cornering or high speed to provide improved handling.

A FIRM RIDE indicator is provided in the indicator lamp module. The indicator is illuminated whenever the position is firm. This includes any time the switch is in the FIRM position or any time the system switches to the firm tuning in the AUTO switch position.

In the event of a system malfunction, the FIRM RIDE indicator will flash on and off. Moving the ride select switch between positions will usually clear any false or intermittent malfunction indications. If the indicator continues to flash, the system should be checked for possible malfunction.

In the AUTO mode, the shock damping control system monitors the following conditions to determine when additional shock damping is required for improved handling:

Any one of the following approximate conditions will cause the shock damping to switch to FIRM:


The shock damping will return to the softer ride a few seconds after these conditions are no longer present, providing vehicle speed has dropped below 134 km/ h (83 mph).


Shock Absorber Electronic Steering Sensor Input

An optical shock absorber electronic steering sensor (photo-cell) has the following characteristics:

Vehicle Speed Sensor Input

The shock absorber electronic system control:

Ride Select Switch Input

The shock absorber, electronic system control responds to the ride select switch to operate in either auto mode or firm ride. While in firm ride, the shock absorber electronic system control illuminates the FIRM RIDE indicator.

Headlamp Input

The shock absorber electronic system control responds to the "Headlamps On" input from the headlamp switch by dimming the firm ride indicator.

Brake Input

The shock absorber electronic system control:

Acceleration Input

The shock absorber electronic system control responds to the powertrain control module acceleration signal. This causes the shock absorber electronic system control to switch the shock absorber electronic actuators to firm. This improves vehicle handling under hard acceleration and supercharger boost periods.
Item
Description
1
Shock Absorber Electronic Actuator
2
Data Link Connector (ARC)
3
Powertrain Control Module
4
Brake Pressure Control Valve
5
Ride Select Switch
6
FIRM RIDE Indicator
7
Shock Absorber Electronic System Control
8
Control Relays
9
Rear Shock Absorber
10
Shock Absorber Electronic Steering Sensor
11
Vehicle Speed Sensor
12
Power Steering Control Valve Actuator
13
Front Shock Absorber



Quick Test of ARC system
Pin
Number
Circuit
Circuit Function
1
Not Used
2
873 (Y/BK)
Reference Voltage
3
Not Used
4
209 (W/P)
STI
5
844 (GY/R)
STO
6
Not Used
  1. Gain access to data link (ARC) connector at back of drivers side front shock actuator cover. Using a jumper wire connect to a known good ground, ground circuit 209 (W/P) Pin 3 at data link connector.
  2. Start engine, run for five seconds Disconnect jumper for one second, reconnect ground to Circuit 209 (W/ P). Record DTCs flashed on instrument cluster FIRM RIDE indicator. I
  3. Refer to Diagnostic Trouble Code (DTC) Directory for proper service procedure per DTCs flashed on instrument cluster FIRM RIDE indicator.

NOTE: The following two steps may be repeated as many times as desired to ensure proper test results. However, once the engine is turned off or ride select switch is moved, you must start test over.

NOTE: The lamp will usually turn on before the wheel has completed the lock turn. This is normal.

  1. With the vehicle at rest and engine running, test the steering sensor by turning the steering wheel from lock in one direction to lock in the other direction, or until FIRM RIDE lamp turns on. FIRM RIDE lamp should turn on for five seconds, then turnoff.
  2. Wait until lamp has turned off from previous-step. Drive the vehicle at any desired speed, above 19 km / h (12mph). FIRM RIDE lamp should come on and stay on until vehicle speed drops below 19 km / h (12 mph).
  3. Stop vehicle and turn engine off. Turn the ride select switch to the AUTO position. Turn ignition switch to the RUN position. Wait until the FIRM RIDE indicator turns off (approximately four seconds). FIRM RIDE lamp turns on for four seconds, then flashes a code, refer to Diagnostic Trouble Code Directory for proper service procedure.

NOTE: The following two steps may be repeated as many times as desired to ensure proper test results. However, once the engine is turned off or ride select switch is moved, you must start test over.

  1. Ensure ride select switch is in the AUTO position. After the FIRM RIDE lamp has turned off , wait five seconds then move ride select switch to the FIRM position. After the lamp turns on, wait five seconds then turn the ride select switch back to the AUTO position. Repeat this test 12 times. FIRM RIDE lamp flashes a code, refer to Diagnostic Trouble Code Directory for proper service procedure.
  2. Move the ride select switch to the AUTO position. After the FIRM RIDE lamp has turned off press the brake pedal until the FIRM RIDE lamp turns on. After the FIRM RIDE lamp turns on, release the brake pedal. FIRM RIDE lamp flashes a code refer to Diagnostic Trouble Code Directory for proper service procedure.
  3. Ensure ride select switch is in the AUTO position. After the FIRM RIDE lamp has turned off, press the accelerator pedal to the floor. The FIRM lamp should turn on. After the FIRM RIDE lamp turns on, release the accelerator pedal. FIRM RIDE lamp flashes a code, refer to Diagnostic Trouble Code Directory for proper service procedure.
  4. Move the ride select switch to the FIRM position. Cycle headlamps on and off while observing FIRM RIDE indicator. FIRM RIDE lamp should be bright with the headlamps off, and dimmer with the headlamps on.
  5. If test has been completed, then the vehicle has passed diagnostics.




    (DTC) DIAGNOSTIC TROUBLE CODE DIRECTORY
(FIRM RIDE Indicator Blinks the Following DTCs Two Times)
Code
Description
All Four Actuator
DTCs Recieved
Concern is in hard or soft damping relay.
11 (1 then 1)
No concern yet.
10 (1)
Concern in LH rear shock absorber electronic actuator.
20 (2)
Concern in RH rear shock absorber electronic actuator.
30 (3)
Concern in RH front .shock absorber. electronic actuator.
40 (4)
Concern in LH front shock absorber electronic actuator.
50 (5)
Short in soft relay.
60 (6)
EVO steering open circuit.
70 (7)
Replace shock absorber electronic system control.
12 (1 then 2)
Soft relay circuitry open/shorted.
13 (1 then 3)
Hard relay circuitry open/shorted.
14 (1 then 4)
Concern in relay control circuitry.
15 (1 then 5)
FIRM RIDE indicator circuit open/ shorted.
16 (1 then 6)
EVO steering circuit short.
22 (2 then 2)
Soft relay short to battery.
23 (2 then 3)
Hard relay short to battery.
25 (2 then 5)
FIRM RIDE indicator short to battery acuator.
26 (2 then 6)
Power steering control valve/switch damaged.
00
Concern is in tester communication circuitry.

If no DTCs are generated as a result of Quick Test, determine the symptom(s) and refer to Ford service manual.