Mitsubishi L200. Manual - part 454

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-72

YES : 

Replace the hydraulic unit assembly 

(integrated with ASTC-ECU) (Refer to 

P.35C-140

.). Then go to Step 6.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Cope with Intermittent 

Malfunctions .).

STEP 6. Check whether the diagnosis code is 
reset.
Check again if the diagnosis code is set.
(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.C1291 set?

YES : 

Go to Step 1.

NO : 

The procedure is complete.

Code No.C1292: CAN communication error

CAUTION

• If there is any problem in the CAN bus lines, 

an incorrect diagnosis code may be set. Diag-
nose the CAN bus lines before the diagnosis 
codes (Refer to GROUP 54C 

− CAN Bus Diag-

nostics Table ).

• Whenever the ECU is replaced, ensure that 

the communication circuit is normal.

OPERATION
ASTC-ECU communicates with other systems and 
sensor via CAN-bus, and shares the necessary infor-
mation for the system operation.

DIAGNOSIS CODE SET CONDITIONS
This code is set if there is a problem in the CAN-bus 
line, or if a problem is found in any ECU or sensor,  
which uses the CAN communication.

PROBABLE CAUSES
The most likely causes for this diagnosis code to set 
is:

• Damaged CAN-bus line

• Damaged wiring harness or connector

• Malfunction of the Engine-ECU.

• Malfunction of the A/T-ECU.

• Malfunction of the steering wheel sensor.

• Malfunction of the G and yaw rate sensor.

• Malfunction of the hydraulic unit assembly (inte-

grated with ASTC-ECU)

DIAGNOSIS

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 lines (Refer to GROUP 
54C 

− CAN Bus Diagnostics Table ). Then 

go to Step 4.

STEP 2. M.U.T.-III other diagnosis code
(1) Turn the ignition switch to the "ON" position.
(2) Check if the diagnosis code is set from all 

system.

(3) Turn the ignition switch to the "LOCK" (OFF) 

position.

Q: Is any diagnosis code set?

YES : 

Diagnose the set diagnosis code, then go 

the Step 4.

NO : 

Go to Step 3.

STEP 3. 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.C1292 set?

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-73

YES : 

Check the engine-ECU, A/T-ECU, ETACS-

ECU, steering wheel sensor and G and yaw 
rate sensor power voltage and earth circuit 
connection. If there is no malfunction, 
replace the hydraulic unit (integrated with 
ASTC

−ECU) (Refer to 

P.35C-140

). Then go 

to Step 4.

NO : 

It can be assumed that this malfunction is 
intermittent. Refer to GROUP 00, How to 
Use Troubleshooting/Inspection Service 
Points 

− How to Cope with Intermittent 

Malfunction .

STEP 4. 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.C1292 set?

YES : 

Go to Step 1.

NO : 

The procedure is complete.

Code No.C1293: Abnormal rear differential lock detection circuit <Vehicle with rear differential lock 
system>

REAR 
DIFFERENTIAL 
LOCK-ECU

REAR 
DIFFERENTIAL
LOCK
DETECTION
SWITCH

ASTC-ECU

Rear differential lock Circuit

Wire colour code
B : Black     LG : Light green     G : Green     L : Blue     W : White     Y : Yellow     SB : Sky blue
BR : Brown     O : Orange     GR : Grey     R : Red     P : Pink     V : Violet     PU : Purple

ACB00847

NOTE

LHD

NOTE

: 

RHD

: 

AC800980

AG

Connector: A-48

(B)

AC504324 AZ

Connectors: F-13, F-13-1

Harness connector
(harness side)

F-13 (GR)
F-13-1

2 1

AC600688

Connector: C-13, C-145 <LHD>

BX

C-13

C-13

C-145 
Harness side

6

2

3

4

10 9 8 7

1
5

C-145

AC600687CV

Connectors: C-29, C-33 <LHD>

16

10

13

4

1112

1 2 3

15

14

5

20

18

17

19

7

6

8 9

C-29

C-33

C-33

C-29

AC509930CC

Connector: C-145 <RHD>

Harness side

6

2

3

4

10 9 8 7

1
5

AC600623DL

Connector: C-13 <RHD>

AC509930CB

Connectors: C-29, C-33 <RHD>

Harness side

C-29

C-33

C-33

C-29

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-74

CAUTION

• If there is any problem in the CAN bus lines, 

an incorrect diagnosis code may be set. Diag-
nose the CAN bus lines before the diagnosis 
codes (Refer to GROUP 54C 

− CAN Bus Diag-

nostics Table .).

• Whenever the ECU is replaced, ensure that 

the communication circuit is normal.

OPERATION
ASTC-ECU detects the rear differential lock opera-
tion status by the following information.

• Rear differential lock detection switch: "ON"

• Rear differential lock indicator lamp: illuminates 

or flashes

If these signals become effective, it is judged that the 
rear differential lock is activated and ABS (EBD)/
ASC/TCL control is prohibited. The ASC indicator 
lamp, the ASC OFF indicator lamp, the ABS warning 
lamp, and brake warning lamp illuminate at the same 
time.

DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set in the following cases. 

• Rear differential lock detection switch: "ON", 

Rear differential lock indicator signal: When the 
"OFF" signal is received for a certain period at the 
same time

• Rear differential lock detection switch: "OFF", 

Rear differential lock indicator signal: When the 
"ON" signal is received for a certain period at the 
same time

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-75

PROBABLE CAUSES

• Damaged wiring harness or connector

• Malfunction of rear differential lock detection 

switch

• Malfunction of rear differential lock-ECU

• Malfunction of ASTC-ECU

DIAGNOSIS

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 3.

NO : 

Repair the CAN bus line (Refer to GROUP 
54C 

− CAN Bus Diagnostics Table .). Then 

go to Step 2.

STEP 2. 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) Start the engine.
(6) Turn the rear differential lock switch to the "ON" 

position.

(7) Drive the vehicle more than 10 seconds at the 

speed exceeds 10 km/h.

(8) Check if the diagnosis code is set.

Q: Is code No.C1293 set?

YES : 

Go to Step 3.

NO : 

The procedure is complete.

STEP 3. Check the M.U.T.-III data list.
(1) Turn the ignition switch to the "ON" position.
(2) Operate the rear differential lock switch, and 

check if the operation status matches the data list 
output.

• Item No.63: Rear differential lock switch

OK:

(Rear differential lock switch: ON): ON
(Rear differential lock switch: OFF): OFF

Q: Is the check result normal?

YES : 

Go to Step 13.

NO : 

Go to Step 4.

STEP 4. Connector check: A-48 ASTC-ECU 
connector, F-13-1 rear differential lock detection 
switch connector, C-145 rear differential lock-
ECU connector, C-13 intermediate connector, C-
29 intermediate connector, C-33 intermediate 
connector, F-13 intermediate connector.

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Repair or replace the damaged 
component(s). Then go to Step 15.

STEP 5. Rear differential lock detection switch 
check
Refer to GROUP 27 

− On-vehicles service, Rear dif-

ferential Lock Detection Switch Check .

Q: Is the check result normal?

YES : 

Go to Step 6.

NO : 

Replace the Rear differential lock detection 
switch (Refer to GROUP 27 

− Rear 

differential lock .). Then go to Step 15.

STEP 6. Resistance measurement at the C-145 
rear differential lock-ECU connector
(1) Disconnect the C-145 rear differential lock-ECU 

connector and measure the resistance at the 
harness side.

(2) Disconnect the A-48 ASTC-ECU connector.
(3) Measure the resistance between the C-145 rear 

differential lock-ECU connector terminal No.10 
and body earth.

OK: No continuity

Q: Is the check result normal?

YES : 

Go to Step 7.

NO : 

Repair the wiring harness. Then go to Step 
15.

STEP 7. Voltage measurement at the C-145 rear 
differential lock-ECU connector
(1) Disconnect the C-145 rear differential lock-ECU 

connector and measure the voltage at the 
harness side.

(2) Disconnect the A-48 ASTC-ECU connector.
(3) Measure the voltage between the C-145 rear 

differential lock-ECU connector terminal No.10 
and body earth.

OK: 1 V or less

Q: Is the check result normal?

YES : 

Go to Step 8.

NO : 

Repair the wiring harness. Then go to Step 
15.