Mitsubishi Electric Lancer Evolution-VII Workshop Manual page 563

52B-32
Code No.42 Power supply circuit system (fuse No.3
circuit)
This code is output when the voltage between terminal IG
No.13) and earth has been below the standard value for 5 seconds.
However, code No.42 is automatically erased and SRS warning lamp goes out
when a normal operation is resumed.If code No.41 and 42 are output at the
same time, check the battery first since the battery voltage may have decreased.
Check the junction block general fuse No.3.
Check when fuse disconnects
D Replace the fuse.
D Turn the ignition switch to the ON position and then turn it
to the OFF position after one minute or more has passed.
Check the fuse.
<Check the circuit between the SRS-ECU and the junction
block>
Measure at the junction block connector C-213.
D Disconnect the junction block connector C-213 and
measure at the harness side.
D Continuity check between terminal 7 and body earth
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: No continuity
NG
Check the other circuits using the general
fuse No.3. (See the Electrical Wiring
Diagram.)
<Check the circuit between the SRS-ECU and the junction
block>
Measure at the C-21 SRS-ECU connector.
D Disconnect the SRS-ECU connector C-21 and measure at
the harness side.
D Continuity check between terminal 13 and body earth
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: No continuity
Replace the SRS-ECU.
SRS -
1
Fuse disconnection
Fuse disconnection
Connector C-213
OK
Connector C-21
OK
Troubleshooting
Possible Cause
(SRS-ECU, terminal D Harness or connector fault
D SRS-ECU inoperable
Fuse is normal
<Check the circuit between the SRS-ECU and the ignition
switch IG
1>
Measure at the SRS-ECU connector C- 21.
D Disconnect the SRS-ECU connector C-21 and measure at
the harness side.
D Connect the negative (- ) terminal of the battery
D Ignition switch: ON
D Voltage between terminal 13 and body earth
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: 9 V or more
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
NG
Check the harness between the SRS-ECU and junction block,
and repair if necessary.
Connector C-21
OK
Replace the SRS-ECU.
NG
Correct