Mitsubishi L200. Manual - part 460

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-96

Q: Is code No.C1394 set?

YES : 

Go to Step 1.

NO : 

The procedure is complete.

Code No.C1396: Engine-ECU malfunction

CAUTION

If there is any problem in the CAN bus lines, an 
incorrect diagnosis code may be set. Diagnose 
the CAN bus lines before the diagnosis codes 
(Refer to GROUP 54C 

− CAN Bus Diagnostics 

Table ).
OPERATION
The hydraulic unit (integrated with ASTC-ECU) com-
municates with the engine-ECU via the CAN bus 
line. ASTC-ECU sends the command to the engine-
ECU to reduce the engine power at the ASC or ATC 
operation.

DIAGNOSIS CODE SET CONDITION
This diagnosis code is set when the ASTC-ECU 
power supply voltage is normal but the engine-ECU 
is abnormal after the engine is started.

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

• Malfunction of the engine-ECU

• Damaged wiring harness or connector

• Malfunction of the hydraulic unit assembly (inte-

grated with 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 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) Check if the diagnosis code is set.
(6) Turn the ignition switch to the "LOCK" (OFF) 

position.

Q: Is code No.C1396 set?

YES : 

Check if a diagnosis code is set by the 

engine-ECU. (Refer to 13A 

− Inspection 

Chart for Diagnosis Codes .)Then go to 
Step 3.

NO : 

The procedure is complete.

STEP 3. 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.C1396 set?

YES : 

Replace the hydraulic unit (integrated with 

ASTC-ECU) (Refer to 

P.35C-140

). Then go 

to Step 4.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Cope with Intermittent 

Malfunctions ).

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.C1396 set?

YES : 

Go to Step 1.

NO : 

The procedure is complete.

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-97

Code No.C1505: Steering Wheel Sensor (Signal Seizure or Abnormal Neutral Point)

 

Code No.C1506: Steering Wheel Sensor (Steering Wheel Sensor Malfunction)

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 ).

• The steering wheel sensor-related diagnosis 

code may be set when diagnosis code 
No.C1506 is set. Diagnose the steering wheel 
sensor first when the steering wheel sensor-
related diagnosis code is set.

OPERATION
The steering wheel sensor detects a steering wheel 
angle and sends it to ASTC-ECU via the CAN bus 
line.

DIAGNOSIS CODE SET CONDITION
These diagnosis codes are set in the following 
cases:

Code No.C1505

• The power supply voltage of ASTC-ECU is nor-

mal, but when the vehicle is driving at the speed 
of 20 to 65 km/h, the G and yaw rate sensor out-
puts the signal of cornering and the steering 
wheel sensor does not change the output.

• The power supply voltage of ASTC-ECU is nor-

mal, but when the vehicle is driving straight at the 
speed of 35 km/h or more, the output of the steer-
ing wheel sensor indicates a turning state.

Code No.C1506

• The power supply voltage of ASTC-ECU is nor-

mal, but the steering wheel sensor is abnormal.

PROBABLE CAUSES
The most likely causes for these diagnosis codes to 
set are:

• Malfunction of steering wheel sensor

• Damaged wiring harness or connector

• Malfunction of the hydraulic unit assembly (inte-

grated with ASTC-ECU)

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics.
(1) Connect M.U.T.-III to the 16-pin diagnosis 

connector.

(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) 

position.

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 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) Check if the diagnosis code is set.
(6) Turn the ignition switch to the "LOCK" (OFF) 

position.

Q: Is code No.C1505 or C1506 set?

YES : 

Replace the steering wheel sensor (Refer to 

P.35C-143

). Then go to Step 4.

NO : 

The procedure is complete.

STEP 3. 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.C1505 or C1506 set?

YES : 

Replace the hydraulic unit (integrated with 

ASTC-ECU) (Refer to 

P.35C-140

). Then go 

to Step 4.

NO : 

The procedure is complete.

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.

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-98

Q: Is code No.No.C1505 or C1506 set?

YES : 

Go to Step 3.

NO : 

The procedure is complete.

Code No.C1620: Engine-ECU communication error

CAUTION

If there is any problem in the CAN bus lines, an 
incorrect diagnosis code may be set. Diagnose 
the CAN bus lines before the diagnosis codes 
(Refer to GROUP 54C 

− CAN Bus Diagnostics 

Table ).
OPERATION
The hydraulic unit (integrated with ASTC-ECU) com-
municates with the engine-ECU via the CAN bus 
line. ASTC-ECU sends the command to the engine-
ECU to reduce the engine power at the ASC or ATC 
operation.

DIAGNOSIS CODE SET CONDITION
This diagnosis code is set when the ASTC-ECU 
power supply voltage is normal but the communica-
tion error with the engine-ECU is present after the 
engine is started.

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

• Malfunction of the engine-ECU

• Damaged wiring harness or connector

• 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 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) Check if the diagnosis code is set.
(6) Turn the ignition switch to the "LOCK" (OFF) 

position.

Q: Is code No.C1620 set?

YES : 

Check if a diagnosis code is set by the 

engine-ECU (Refer to 13A 

− Inspection 

Chart for Diagnosis Codes ). Then go to 
Step 3.

NO : 

The procedure is complete.

STEP 3. 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.C1620 set?

YES : 

Replace the hydraulic unit (integrated with 

ASTC-ECU) (Refer to 

P.35C-140

). Then go 

to Step 4.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Cope with Intermittent 

Malfunctions ).

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.C1620 set?

YES : 

Go to Step 1.

NO : 

The procedure is complete.

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-99

Code No. C1860: High voltage at ASTC-ECU power supply

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

• The ASTC-ECU is energized by the ignition 

switch (IG1) through multi-purpose fuse No.15 
and the ASTC-ECU terminal 25.

• The wheel speed sensors are energised via 

ASTC-ECU terminal No. 25.

DIAGNOSIS CODE SET CONDITION
This diagnosis code is set when the power supply 
voltage of the ASTC-ECU is abnormally high.

PROBABLE CAUSES

• Battery abnormality

• ASTC-ECU malfunction

• Charging system failed

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

Q: Is the diagnosis code No. C1860 set?

YES : 

Go to Step 3.

NO : 

This diagnosis is complete.

STEP 3. Battery check
Refer to GROUP 54A 

− Battery Test .

Q: Is the battery in good condition?

YES : 

Go to Step 5.

NO : 

Charge or replace the battery. Then go to 
Step 4.

STEP 4. Charging system check
Refer to GROUP 16 

− Charging System .

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Repair or replace the charging system 
component(s).

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 the diagnosis code No. C1860 set?

YES : 

Replace the hydraulic unit (integrated with 

ASTC-ECU) (Refer to 

P.35C-140

.). Then go 

to Step 6.

NO : 

The trouble can be an intermittent 
malfunction (Refer to GROUP 00 

− How to 

Use Troubleshooting, How to Cope with 
Intermittent Malfunctions .).

STEP 6. 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 the diagnosis code No. C1860 set?

YES : 

Return to Step 1.

NO : 

This diagnosis is complete.