Mitsubishi Evolution X. Manual - part 815

ON-VEHICLE SERVICE

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ACTIVE SKID CONTROL SYSTEM (ASC)

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14."Executed: The command was executed." will be shown. 

Then press "OK" button.

15.Learning neutral point complete
16.Turn the ignition switch to "LOCK" (OFF) position and then 

disconnect the scan tool.

STEERING WHEEL SENSOR CALIBRATION

M1355009200156

CAUTION

After the next operation has been completed, carry out the 
following two operations:

• Front alignment
• Steering wheel sensor (column switch assembly) 

replacement, removal and installation

• ASC-ECU replacement

1. Revise the neutral point which the steering wheel sen-

sor stores. 

2. Reset the steering angle compensation value which the 

ASC-ECU stores.

CAUTION

• Prior to calibration, check that no steering wheel sen-

sor-related diagnostic trouble codes are set.

• If diagnostic trouble codes other than C121A have set, 

proceed to the relevant troubleshootings.

1. Place the vehicle on a level surface with its road wheels in 

the straight ahead position.

2. Turn the ignition switch "LOCK" (OFF) position.

CAUTION

Before connecting or disconnecting the scan tool, turn the 
ignition switch to the "LOCK" (OFF) position.
3. Set the scan tool with the ignition at "LOCK" (OFF).
4. Turn the ignition switch "ON" position.
5. Select the relevant system from the menu.
6. Select "Steering angle sensor" from the system list in 

"System select", and press "OK" button.

7. Select "Special function" under "Steering angle sensor".
8. Select "SAS Calibration" under "Special function".

NOTE: If the steering angle sensor neutral point has been 
learned, the display will show "If SAS needs re-calibration, 
execute SAS calibration after executing SAS initialization". If 
yes, press "OK" button.

9. As "SAS initialization" is selected under "SAS Calibration", 

press "OK" button.
NOTE: At this time, if the steering angle sensor neutral point 
has been learned, the display will show "Do you want to 
start? Note This operation will dear DTCs". Then, press 
"OK" button.

10.The display should show "Completed." Press "OK" button.
11.Press the OK button.

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12.The display should show "SAS Calibration: Do you want to 

start?". Then press the OK button.
NOTE: Please execute after making a tire and a steering 
wheel straight.

13.The display should show "Completed." Press "OK" button. 
14.Turn the ignition switch to "LOCK" (OFF) position, and then 

turn the ignition switch ON again.

15.Select the relevant system from the menu.
16.Select "ABS/ASC/ASTC/WSS" from the system list under 

"System select", and press "OK" button.

17. Select "Special function" under "ABS/ASC/ASTC/WSS".
18.Select "Sensor calibration" under "Special function".
19.Select "SAS calibration" under "Sensor calibration", and 

press "OK" button.

20.The screen displays "SAS calibration: The selected 

command will be executed. Are you sure? Caution: Confirm 
the execution conditions." Then press "OK" button.

21."Executed: The command was executed." will be shown. 

Then press "OK" button.

22.Select "Diagnostic trouble code" under 

"ABS/ASC/ASTC/WSS". If the diagnostic trouble code 
"C2205 SAS internal failure (past trouble)" is set, clear it.

23.Learning neutral point complete
24.Turn the ignition switch to "LOCK" (OFF) position and then 

disconnect the scan tool.

MASTER CYLINDER BRAKE FLUID PRESSURE 
SENSOR CALIBRATION

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CAUTION

• Before performing the calibration, check that the wheel 

cylinder brake fluid pressure sensor-related diagnostic 
trouble code is not set.

• Always perform the calibration with the brake pedal 

released (stoplight switch is turned off).

• After the operation below is completed, perform the cal-

ibration to make ASC-ECU to learn the neutral point of 
the wheel cylinder brake fluid pressure sensor.

1. Troubleshooting for diagnostic trouble code No. 

C123A

2. ASC-ECU replacement

1. Park the vehicle on a level surface.
2. Turn the ignition key to the ON position.
3. Turn the ignition key to the LOCK (OFF) position.

CAUTION

Before connecting or disconnecting scan tool MB991958, 
always turn the ignition switch to the LOCK (OFF) position.
4. Check that the ignition key is in the LOCK (OFF) position, 

and then set scan tool MB991958.

5. Turn the ignition switch to the ON position.

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6. On the Menu, select "System selection."
7. On the "System selection," select "ABS/ASC/ASTC/WSS" in 

the system list, and then click the "OK" button.

8. Select "Special function" in the "ABS/ASC/ASTC/WSS" field.
9. In the "Special function," select "Learn sensor neutral 

position."

10.Among the selected items, select "Learn M/C pressure 

sensor neutral position," and then press the "OK" button.

11.When a message "Learn M/C pressure sensor neutral 

position: Are you sure to execute the selected item? 
Caution: Check the execution conditions" is displayed, press 
the "OK" button.

12.When a message "Command execution: Command has 

been executed" is displayed, press the "OK" button.

13.The neutral point is learned.
14.Turn the ignition key to the LOCK (OFF) position, and then 

remove the scan tool from the vehicle.

CALIBRATION OF CUT VALVE AND INLET VALVE

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CAUTION

• Before the calibration work of the cut valve and inlet 

valve, check that no diagnostic trouble code is set 
relating to the cut valve, inlet valve, motor system, 
power supply system, or ECU system.

• Always perform the calibration of cut valve and inlet 

valve with the brake pedal released (stoplight switch is 
turned off).

• If any diagnostic trouble code other than No. C2002 is 

also set, always perform the diagnosis of the diagnos-
tic trouble code other than No. C2002 first.

• After the replacement of ASC-ECU, the calibration of 

cut valve and inlet valve must be performed with the 
new ASC-ECU.

• When the cut valve calibration is performed, the cali-

bration of master cylinder fluid pressure sensor is also 
executed at the same time.

• When the cut valve calibration is not completed, the 

inlet valve calibration cannot be performed.

• After the completion of following works, always per-

form the calibration of cut valve and inlet valve.

1. Diagnosis for the diagnostic trouble code No. C2002 

is performed.

2. ASC-ECU replacement

1. Park the vehicle on a level surface.
2. Turn the ignition key to the ON position.
3. Turn the ignition key to the LOCK (OFF) position.

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CAUTION

Before connecting or disconnecting scan tool, always turn 
the ignition switch to the LOCK (OFF) position.
4. Check that the ignition key is in the LOCK (OFF) position, 

and then set scan tool.

5. Turn the ignition switch to the ON position.
6. On the Menu, select "System selection."
7. On the "System selection," select "ABS/ASC/ASTC/WSS" in 

the system list, and then click the "OK" button.

8. Select "Special function" in the "ABS/ASC/ASTC/WSS" field.
9. In the "Special function," select "Learn valve fluid pressure."
10.Among the selected items, select "Cut valve fluid pressure," 

and then press the "OK" button.

11.When a message "Cut valve fluid pressure: Are you sure to 

execute the selected item? Caution: Check the execution 
conditions" is displayed, press the "OK" button.

12.When a message "Command execution: Command has 

been executed" is displayed, press the "OK" button.

13.Check that the message changes from "Under execution" to 

"Complete."
NOTE: The cut valve fluid pressure learning requires 
approximately 20 seconds.

14.Among the selected items, select "Inlet valve fluid 

pressure," and then press the "OK" button.

15.When a message "Inlet valve fluid pressure: Are you sure to 

execute the selected item? Caution: Check the execution 
conditions" is displayed, press the "OK" button.

16.When a message "Command execution: Command has 

been executed" is displayed, press the "OK" button.

17.Check that the message changes from "Under execution" to 

"Complete."
NOTE: The inlet valve fluid pressure learning requires 
approximately 20 seconds.

18.The valve fluid pressure learning is complete.
19.Turn the ignition key to the LOCK (OFF) position, and then 

remove the scan tool from the vehicle.