Mitsubishi Lancer Evolution X. Manual - part 144
DIAGNOSIS
TSB Revision
ACTIVE STABILITY CONTROL SYSTEM (ASC)
35C-41
CAUTION
• If there is any problem in the CAN bus lines, an incor-
rect diagnostic trouble code may be set. Prior to this
diagnosis, diagnose the CAN bus lines.
• Whenever the ECU is replaced, ensure that the CAN
bus lines are normal.
• When the hydraulic unit (integrated with ASC-ECU) is
replaced, always perform the calibration of steering
wheel sensor, G and yaw rate sensor, brake fluid pres-
sure sensor, cut valve, and inlet valve.(Refer to
.)
.
CIRCUIT OPERATION
• Each wheel speed detecting section is a kind of a pulse
generator. It consists of the encoder (plate on which the
north and south pole of magnet are arranged alternately) for
detecting the wheel speed, which rotates at the same speed
of the wheels, and the wheel speed sensor. This detecting
section outputs the frequency pulse signals in proportion to
the wheel speed.
• The pulse signals generated by the wheel speed detecting
section are sent to ASC-ECU. ASC-ECU uses the fre-
quency of the pulse signals to determine the wheel speed.
.
DTC SET CONDITIONS
ASC-ECU monitors the electric current in each wheel speed
sensor circuit. If an open or short circuit in the wheel speed
sensor circuit is detected, ASC-ECU sets a corresponding
diagnostic trouble code.
.
PROBABLE CAUSES
Current trouble
• Damaged wiring harness and connectors
• Noise interference
• Malfunction of wheel speed sensor
• ASC-ECU malfunction
Past trouble
• Carry out the diagnosis with a particular emphasis on the
wiring harness and connector failures between ASC-ECU
and the wheel speed sensor. For diagnosis procedures,
refer to How to Treat Past Trouble (GROUP 00 − How to
Use Troubleshooting/Inspection Service Points
).
DIAGNOSIS
Required Special Tools:
• MB991958 Scan Tool (M.U.T.-III Sub Assembly)
• MB991824: Vehicle Communication Interface (V.C.I.)
• MB991827 M.U.T.-III USB Cable
• MB991910 M.U.T.-III Main Harness A
• MB991997: ASC check harness