Mitsubishi Lancer (4A9 engine). Manual - part 45
TROUBLESHOOTING
ACTIVE STABILITY CONTROL SYSTEM (ASC)
35C-33
DIAGNOSIS CODE SET CONDITIONS
ASC-ECU monitors the voltage fluctuation in each
wheel speed sensor circuit. If ASC-ECU detects the
open or short circuit in the circuit, it will set a diagno-
sis code.
PROBABLE CAUSES
Current trouble
• Damaged wiring harness and connectors
• Noise interference
• Malfunction of wheel speed sensor
• Malfunction of ASC-ECU
Past trouble
• Carry out diagnosis with particular emphasis on
wiring harness and connector failures between
ASC-ECU and the wheel speed sensor. For diag-
nosis procedures, refer to How to treat past trou-
ble (GROUP 00
− How to Use Troubleshooting/
How to Treat Past Trouble ).
DIAGNOSTIC 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
Q: Is the diagnosis code No. C102B set?
YES :
Go to Step 3.
NO :
This diagnosis is complete.
STEP 3. M.U.T.-III data list
Check the following data list (Refer to
• Item No.04: RR wheel speed sensor
Q: Is the check result normal?
YES :
Go to Step 12.
NO :
Go to Step 4.
STEP 4. Voltage measurement at the A-58 ASC-
ECU connector
AC606869DE
ASC-ECU
MB991997
Check harness
A-58 ASC-ECU
harness connector
(1) Disconnect the ASC-ECU connector, connect
special tool ASC check harness (MB991997) to
the harness-side connector, and then measure
the voltage at the special tool connector side.
NOTE: Do not connect the special tool to ASC-
ECU.
(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between the rear wheel
speed sensor <RH> power supply terminal
(signal terminal) No.43 and the body earth, and
between the rear wheel speed sensor <RH>
earth terminal No.42 and the body earth.
OK: 1 V or less
Q: Is the check result normal?
YES :
Go to Step 5.
NO (Not normal at the terminal No.43 or No.42) :
Go to Step 6.