Mitsubishi Lancer Evolution-VII Workshop Manual page 995

MANUAL TRANSMISSION - Troubleshooting <ACD>
Code No.31 Steering wheel sensor <ST-1, ST-2, ST-N>
system
Code No.31 is output when open circuit or short circuit of the steering wheel
sensor output line (ST-1, ST-2, or ST-N) occurs.
MUT-II Diagnosis Code
D Are the ABS Diagnosis Code
Nos.81, 82, 83 output?
NO
MUT-II Data List
D No.21 Steering wheel sensor
voltage <ST-1>
D No.22 Steering wheel sensor
voltage <ST-2>
D No.23 Steering wheel sensor
voltage <ST-N>
OK: Refer to P.22A-35 (Data
List Reference Table).
OK→Intermittent malfunction (Refer
to GROUP 00 - Points to Note for
Intermittent Malfunctions)
NG
Measure at 4WD-ECU connector C-43.
D Measure the ECU terminal voltage.
D Ignition switch: ON
(1) Voltage between terminal 33 and earth (Steering wheel
sensor <ST-1>)
(2) Voltage between terminal 34 and earth (Steering wheel
sensor <ST-2>)
(3) Voltage between terminal 44 and earth (Steering wheel
sensor <ST-N>)
OK: When the steering wheel is turned, changes at
approx. 1.5 V – 3.5 V.
NG (Changes at 1 V
- 4.5 V or more)
Measure at steering wheel sensor connector C-230.
D Disconnect the connector and measure at the
harness side.
D Ignition switch: ON
(1) Voltage between terminal 2 and earth
OK: System voltage
(2) Resistance between terminal 3 and body earth
OK: 2 Ω or less
Check the following connectors:
<L.H. drive vehicles> C-230, C-128, C-43
<R.H. drive vehicles> C-230, C-43
NG→Repair
Check the harness between 4WD-ECU and steering
wheel sensor.
D Check for open circuit, short circuit, and damage of
the output line.
NG→Repair
Replace the steering wheel sensor.
YES
Measure at Steering wheel sensor
connector C-230.
D Disconnect the connector and
measure at the harness side.
D Ignition switch: ON
D Voltage between terminal 2 and
earth
OK: System voltage
D Resistance between terminal 3
and body earth
OK: 2 Ω or less
Check the following connector:
C-230
NG→Repair
Replace the Steering wheel sensor.
NG (No change from 0 V or
from above 4.5 V)
OK
OK
OK
Probable cause
D Steering wheel sensor fault
D Harness or connector fault
D 4WD-ECU fault
NG
OK
OK
OK
Check the following connector: C-43
NG→Repair
MUT-II Data List
D No.21 Steering wheel sensor voltage <ST-1>
D No.22 Steering wheel sensor voltage <ST-2>
D No.23 Steering wheel sensor voltage <ST-N>
OK: Refer to P.22A-35 (Data List Reference Table).
NG→Replace the 4WD-ECU.
OK→Intermittent malfunction (Refer to GROUP 00 - Points to
Note for Intermittent Malfunctions)
(1) NG
Check the following connectors: C-230, C-102, C-209,
C-210
NG→Repair
(2) NG
Check the harness between the steering wheel sensor and
ignition switch.
D Check for open circuit, ground and damage of the power
line.
NG→Repair
Check the following connector: C-230, C-08
NG→Repair
Check the harness between the steering wheel sensor and
body earth.
D Check for open circuit and damage of the earth line.
NG→Repair
22A-15
Check the following connectors:
C-230, C-102, C-209, C-210
NG→Repair
OK
Check the harness between the
ignition switch and steering wheel
sensor.
D Check for open circuit and
damage on power line.
NG→Repair
OK
OK
OK