Mitsubishi L200. Manual - part 463
TROUBLESHOOTING
ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)
35C-108
Code No.U1120: Engine malfunction detection
CAUTION
• If diagnosis code No.U1120 is set in the
ASTC-ECU, always diagnose the CAN main
bus line. If there is any fault in the CAN bus
lines, an incorrect diagnosis code may be set.
• Whenever the ECU is replaced, ensure that
the communication circuit is normal.
DIAGNOSIS CODE SET CONDITION
The ASTC-ECU receives engine system-related sig-
nals from the Engine-ECU via CAN bus lines. If a fail-
safe related data is contained in the signal from the
Engine-ECU, diagnosis code No.U1120 will be
stored.
PROBABLE CAUSES
• Damaged harness or connector.
• Malfunction of the Engine-ECU.
• Malfunction of the ASTC-ECU.
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES :
Go to Step 2.
NO :
Repair the CAN bus line (Refer to GROUP
54C
− CAN Bus Diagnostics Table ). Then
go to Step 5.
STEP 2. M.U.T.-III other diagnosis code
Check whether the diagnosis code No. U1120 is set
by another ECU.
Q: Is the diagnosis code set?
YES :
Replace the Engine-ECU (Refer to GROUP
13A
− Engine-ECU ). Then go to Step 5.
NO :
Go to Step 3.
STEP 3. M.U.T.-III other diagnosis code
Check whether the diagnosis code is set by the
Engine-ECU.
Q: Is any diagnosis code set?
YES :
Perform troubleshooting for Engine-ECU
(Refer to GROUP 13A
− Troubleshooting ).
Then go to Step 5.
NO :
Go to Step 4.
STEP 4. M.U.T.-III diagnosis code
(1) Turn the ignition switch to the "ON" position.
(2) Erase the diagnosis code.
(3) Turn the ignition switch to the "LOCK" (OFF)
position.
(4) Turn the ignition switch to the "ON" position.
(5) Check if the diagnosis code is set.
(6) Turn the ignition switch to the "LOCK" (OFF)
position.
Q: Is code No.U1120 set?
YES :
Replace the hydraulic unit (integrated with
ASTC-ECU) (Refer to
). Then go
to Step 5.
NO :
Intermittent malfunction (Refer to GROUP
00
− How to Cope with Intermittent
Malfunction ).
STEP 5. Check whether the diagnosis code is
reset.
(1) Turn the ignition switch to the "ON" position.
(2) Erase the diagnosis code.
(3) Turn the ignition switch to the "LOCK" (OFF)
position.
(4) Turn the ignition switch to the "ON" position.
(5) Check if the diagnosis code is set.
(6) Turn the ignition switch to the "LOCK" (OFF)
position.
Q: Is code No.U1120 set?
YES :
Go to Step 1.
NO :
The procedure is complete.
Code No.U1190: ETACS signal receiving error
CAUTION
• If diagnosis code No.U1190 is set in the
ASTC-ECU, always diagnose the CAN main
bus line. If there is any fault in the CAN bus
lines, an incorrect diagnosis code may be set.
• Whenever the ECU is replaced, ensure that
the communication circuit is normal.
DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set if ASTC-ECU cannot
receive the signal sent from the ETACS-ECU for a
certain period.