Mitsubishi Electric Lancer Evolution-VII Workshop Manual page 572

INSPECTION CHART FOR TROUBLE SYMPTOMS
Study the trouble symptoms and check according to the inspection procedure chart.
Trouble
Communication with MUT-II is impossible.
SRS warning lamp does not illuminate.
SRS warning lamp does not go out.
INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
Inspection Procedure 1
Communication with MUT-II is impossible.
When communication with all systems is impossible, diagnosis circuit is
suspected as faulty.
When only communication with SRS air bags is impossible, open in diagnosis
output circuit or power supply circuit including earth circuit may be present.
Is communication by MUT-II possible when the ignition switch
is ON?
<Check the SRS-ECU MUT-II communication circuit>
Measure at the SRS-ECU connector C-21 and diagnosis
connector C-22 .
D Disconnect SRS-ECU connector C-21 and measure at the
harness side and diagnosis connector C-22.
D Continuity check between the following terminals
C-21 connector
20 –
Caution
Do not directly insert a probe or other devices at the
front of the connector to avoid a possible decrease in
the contact pressure.
OK: Continuity (2Ω or less)
Connector C-22
<Check the SRS-ECU power supply circuit (including earth
circuit)>
Measure at the C-21 SRS-ECU connector.
D Disconnect the SRS-ECU connector C-21 and measure at
the harness side.
Caution
Do not directly insert a probe or other devices at the
front of the connector to avoid a possible decrease in
the contact pressure.
(1) Continuity between terminal
7 and body earth
OK: Continuity (2Ω or less)
D Connect the negative (- ) terminal
of the battery
D Ignition switch:ON
(2) Voltage between terminal 13
and body earth
OK: 9 V or more
(3) Voltage between terminal 16
and body earth
OK: 9 V or more
SRS -
YES
C-22 connector
7
Connector C-21
OK
Connector C-21
Connector C-21
Troubleshooting
Inspection procedure No(s).
1
See diagnosis code No.43.
See diagnosis code No.43, 44.
Probable cause
D Harness, connector malfunction
D SRS-ECU malfunction
D MUT ROM pack unmatching
NO
Check the MUT-II diagnosis circuit, and repair if necessary.
NG
Check connector: C-21, C-26, C-22
OK
Check the trouble
symptoms.
NG
Check the harness between the SRS-ECU and the diagnosis
connector, and repair if necessary.
(1) NG
Check connector: C-21
OK
Check the trouble symptoms.
NG
Check the harness between the SRS-ECU and earth, and
repair if necessary.
(2), (3)
NG
Check connector: C-21, C-213, C-210
OK
Check the trouble symptoms.
NG
Check the harness between the SRS-ECU and the ignition
switch IG , and repair if necessary.
1
OK
Replace the SRS-ECU.
52B-41
Reference page
52B-41
52B-33
52B-33
NG
Correct
NG
Correct
NG
Correct