Mitsubishi L200. Manual - part 442
TROUBLESHOOTING
ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)
35C-24
CAUTION
• If there is any problem in the CAN bus lines,
an incorrect diagnosis code may be set. Prior
to this diagnosis, diagnose the CAN bus lines
(Refer to GROUP 54C
− CAN Bus Diagnostics
Table .).
• Before replacing the ECU, ensure that the
communication circuit is normal.
OPERATION
• A toothed ABS rotor generates a voltage pulse as
it moves across the pickup field of each wheel
speed sensor.
• The wheel speed sensor transmit the frequency
of the pulses to the ASTC-ECU.
• The hydraulic unit assembly (integrated with
ASTC-ECU) modulates the amount of braking
force individually applied to each wheel cylinder.
DIAGNOSIS CODE SET CONDITION
Diagnosis code No.C1200 is set when signal is not
input due to breakage of the wire of the wheel speed
sensor without the output of the code No.C1202.
PROBABLE CAUSES
Current trouble
• Damaged wiring harness and connectors
• Wheel speed sensor malfunction
• ASTC-ECU malfunction
Past trouble
• Carry out diagnosis with particular emphasis on
wiring harness and connector failures between
ASTC-ECU and the wheel speed sensor. For
diagnosis procedures, refer to How to treat past
trouble (GROUP 00
− How to Cope with Intermit-
tent Malfunctions .).
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnosis
Use M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES :
Go to Step 3.
NO :
Repair the CAN bus lines (Refer to GROUP
54C
− CAN Bus Diagnostics Table .). On
completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting
CAN bus lines
(1) Erase the diagnosis code.
(2) Drive the vehicle at 15 km/h or more.
NOTE: The ABS warning lamp does not turn OFF
in some cases unless the vehicle runs at 15 km/h
or higher.
Q: Is the diagnosis code No.C1200 set?
YES :
Go to Step 3.
NO :
The procedure is complete.
STEP 3. M.U.T.-III diagnosis code
Check that the diagnosis code No.C1202 are also
set.
Q: Is the diagnosis code No.C1202 also set?
YES :
Perform the diagnosis for the diagnosis
code No.C1202 (Refer to
.).
NO :
Go to Step 4.
STEP 4. M.U.T.-III data list
Check the following data list (Refer to
• Item No.02: FR wheel speed sensor
Q: Is the check result normal?
YES :
Go to Step 8.
NO :
Go to Step 5.
STEP 5. Connector check: A-48 ASTC-ECU
connector, A-125 front wheel speed sensor (RH)
connector
Q: Is the check result normal?
YES :
Go to Step 6.
NO :
Repair the defective connector. Then go to
Step 9.
STEP 6. Resistance measurement at the A-48
ASTC-ECU connector
(1) Disconnect the A-48 ASTC-ECU connector.
(2) Measure the resistance between the A-48 ASTC-
ECU connector terminal No.6 and terminal No.7.
OK: Continuity
Q: Is the check result normal?
YES :
Go to Step 7.
NO :
Repair the wiring harness. Then go to Step
9.
STEP 7. Check for wheel speed sensor as a
single unit
Refer to
Q: Is the check result normal?
YES :
Go to Step 8.
NO :
Replace the wheel speed sensor (Refer to
.). Then go to Step 9.