MITSUBISHI LANCER EVOLUTION 2007 Service Repair Manual

SRS -Troubleshooting52B-17

spring>
Measure at the SRS-ECU connector C-21 and the clock
spring connector C-204.
DDisconnect the SRS-ECU connector C-21 and the clock
spring connector C-204 and measure at the harness side.
DContinuity check between the following terminals
Connector C-21 Connector C-204
11 – 2
12 – 1
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 (2Ωor less)
NG
Correct
Check connector:C-21, C-204
OK
Check the trouble
symptoms.
NG
Check the harness between the clock spring and the
SRS-ECU, and repair if necessary. NG
Connector C-21Connector C-204
MUT-II self-diag code
DRelease the clock spring connector (2 - pin) C-204.
DConnect the dummy resistor (MB991865) to the resistor harness
(MB991866).
DInsert the resistor harness
(MB991866) behind the harness side connector C-204.
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.
DConnect the negative ( - ) terminal of the battery
DCheck the diagnosis code again after erasing the memory.
Is code No.22 output?
YES
Check the clock spring (Refer to P.52B-59.)
NOYES
Replace the clock spring.Replace the driver’s air bag module
(squib).NO
Replace the SRS-ECU.
OK Resistor harness
(MB991866)
Clock spring harness
side connector C - 204 Dummy resistor
(MB991865)
resistance (3Ω)

SRS -Troubleshooting52B-18


MUT-II self-diag code
DDisconnect the clock spring connector No.1 (connector connected with
the air bag module).
DConnect the dummy resistor (MB991865) to the resistor harness
(MB991866).
DInsert the resistor harness (MB991866) behind the clock spring
connector No.1.
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.
DConnect the negative ( - ) terminal of the battery
DCheck the diagnosis code again after erasing the memory.
Is code No.22 output? Dummy resistor
(MB991865)
resistance (3Ω)
1
YESNO
Replace the steering wheel - driver’s air bag module assembly. Resistor harness
(MB991866)
Go to Next Page
MUT-II self-diag code
DRelease the clock spring connector (2 - pin) C-204.
DConnect the dummy resistor (MB991865) to the resistor harness
(MB991866).
DInsert the resistor harness
(MB991866) behind the harness side connector C-204.
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.
DConnect the negative ( - ) terminal of the battery
DCheck the diagnosis code again after erasing the memory.
Is code No.22 output?
YES
Replace the clock spring.NO
Resistor harness
(MB991866)
C-204 clock spring
harness side connector Dummy resistor
(MB991865)
resistance (3Ω)

SRS -Troubleshooting52B-19
spring>
Measure at the C-21 SRS-ECU connector and C-204 clock
spring connector.
DDisconnect the SRS-ECU connector C-21 and the clock
spring connector C-204 and measure at the harness side.
DContinuity check between the following terminals
C-21 connector C-204 connector
11 – 2
12 – 1
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 (2Ωor less)
NG
Correct
Check connector:C-21, C-204
OK
Check the trouble
symptoms.
NG
Check the harness between the clock spring and the
SRS-ECU, and repair if necessary.
YES
From Previous Page
NG
Connector C-21Connector C-204
Replace the SRS-ECU.
OK

SRS -Troubleshooting52B-20
Code No.24 Front passenger’s air bag module (squib)
systemPossible Cause
This code is output when short circuit occurs between terminals of the
SRS-ECU front passenger’s air bag (squib) circuit.
However, SRS warning lamp goes out when a normal operation is resumed
(diagnosis code is not cleared.)DConnector engagement faulty or short bar faulty*
DShort circuit between terminals of the front
passenger’s air bag (squib) circuit
DFaulty connector
DSRS-ECU inoperable
NOTE:
*: The connector of the squib circuit contains a short bar (short-circuiting the positive (+) cable and the
negative ( - ) cable to avoid an erroneous deployment caused by static electricity when a connector is
not connected). Thus, when a connector is connected, the short bar may not be released due to improper
engagement of the connector or faulty connector as shown in the illustration below. Disconnect the connector
as shown in the illustration below, then reconnect it. Check that a diagnosis code is output again after
erasing the memory. If the diagnosis code is not output, the above-mentioned code is output due to
improper engagement of the connector.
C-21
SRS-ECUC-109
Front passenger’s air bag module

SRS -Troubleshooting52B-21
OK
passenger’s air bag module>
Measure at the C-21 SRS-ECU connector.
DDisconnect the SRS-ECU connector C-21.
DDisconnect the front passenger’s air bag module connector
C-109.
Caution
Disconnect the connector and short-circuit the squib
circuit before releasing the short bar of the SRS-ECU
connector in the following operation.
DCable bands between terminals 9, 10 and the short bar
(width:3 mm, thickness:0.5 mm) between terminals 11 and
12 and the short bar, and release the short bar.
(See Figure A.)
Caution
As the short bar may not be releasable if inserted
insufficiently, insert more than 4 mm.
DMeasure at the harness side
DContinuity check between terminals 9 and 10
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
YESNO
Replace the front passenger’s seat air bag module (squib).
Resistor harness
(MB991866) Dummy resistor
(MB991865)
resistance (3Ω)
Instrumental panel
wiring harness
Front passenger’s air bag
module connector
MUT-II self-diag code
DConnect the dummy resistor (MB991865) to the resistor harness
(MB991866).
DDisconnect the front passenger’s air bag module connector C-109
and insert the resistor harness (MB991866) behind the harness side
connector.
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.
DConnect the negative ( - ) terminal of the battery
DCheck the diagnosis code again after erasing the memory.
Is code No.24 output?
Check the trouble
symptoms.
NG
Check the harness between the front passenger’s air bag
module and the SRS-ECU, and repair if necessary. NG
YESNG
Correct
Check connector:C-21, C-109
Connector C-21
Figure A
Terminal
Short bar
Front view of C-21
SRS-ECU connector
(harness side).
Cable band
and etc.Section
A-A
4 mm or more
A
A
Replace the SRS-ECU.

SRS -Troubleshooting52B-22
Code No.25 Front passenger’s air bag module (squib)
systemPossible Cause
This code is output when open circuit occurs in the SRS-ECU front passenger’s
air bag (squib) circuit.
However, SRS warning lamp goes out when a normal operation is resumed
(diagnosis code is not cleared.)DOpen in the front passenger’s air bag module
(squib) circuit
DConnector improper contact
DSRS-ECU inoperable
NG
passenger’s air bag module>
Measure at the SRS-ECU connector C-21 and front
passenger’s air bag module connector C-109 .
DDisconnect the SRS-ECU connector C-21 and the front
passenger’s air bag module connector C-109 , and
measure at the harness side.
DContinuity check between the following terminals
Connector C-21 Connector C-109
9–2
10 – 1
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 (2Ωor less)
YESNO
Replace the front passenger’s seat air bag module (squib).

MUT-II self-diag code
DConnect the dummy resistor (MB991865) to the resistor harness
(MB991866).
DDisconnect the front passenger’s air bag module connector C-109
and insert the resistor harness (MB991866) behind the harness side
connector.
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.
DConnect the negative ( - ) terminal of the battery
DCheck the diagnosis code again after erasing the memory.
Is code No.25 output?
Replace the SRS-ECU.
Check the trouble
symptoms.
NG
Check the harness between the front passenger’s air bag
module and the SRS-ECU, and repair if necessary.
OKNG
Correct
Check connector:C-21, C-109
OK
Resistor harness
(MB991866) Dummy resistor
(MB991865)
resistance (3Ω)
Instrumental panel
wiring harness
Front passenger’s air bag
module connector
Connector C-21Connector C-109

SRS -Troubleshooting52B-23
Code No.26 Driver’s seat belt pre-tensioner (squib)
systemPossible Cause
This code is output when short circuit occurs between terminals of the
SRS-ECU driver’s seat belt pre-tensioner (squib) circuit.
However, SRS warning lamp goes out when a normal operation is resumed
(diagnosis code is not cleared.)DConnector engagement faulty or short bar faulty*
DShort circuit between terminals of the driver’s seat
belt pre-tensioner (squib) circuit
DFaulty connector
DSRS-ECU inoperable
NOTE:
*: The connector of the squib circuit contains a short bar (short-circuiting the positive (+) cable and the
negative ( - ) cable to avoid an erroneous deployment caused by static electricity when a connector is
not connected). Thus, when a connector is connected, the short bar may not be released due to improper
engagement of the connector or faulty connector as shown in the illustration below. Disconnect the connector
as shown in the illustration below, then reconnect it. Check that a diagnosis code is output again after
erasing the memory. If the diagnosis code is not output, the above-mentioned code is output due to
improper engagement of the connector.
C-41C-133*1,
C-112*2
SRS-ECU
Driver’s seat belt
pre-tensioner
NOTE
*1: L.H. drive vehicles
*2: R.H. drive vehicles
D-28*1,
D-26*2

SRS -Troubleshooting52B-24
OK
YESNO
Replace the driver’s seat belt pre-tensioner.

MUT-II self-diag code
DConnect the dummy resistor (MB991865) to the resistor harness
(MB991866).
DDisconnect the driver’s seat belt pre-tensioner connector D-28*
1and
D-26*2and connect to the resistor harness (MB991866) behind the
harness side connector.
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.
DConnect the negative ( - ) terminal of the battery
DCheck the diagnosis code again after erasing the memory.
Is code No.26 output?
Replace the SRS-ECU.
Check the trouble
symptoms.
NG
Check the harness between the driver’s seat belt
pre-tensioner and the SRS-ECU, and repair if necessary.
YESNG
Correct
Check connector:D-28*1,D-26*2,C-133*1, C-112*2, C-41 Driver’s seat belt
pre-tensioner connector
seat belt pretensioner>
Measure at the SRS-ECU connector C-41.
DDisconnect the SRS-ECU connector C-41.
DDisconnect the driver’s seat belt pre-tensioner connector
D-28*
1and D-26*2.Caution
Disconnect the connector and short-circuit the squib
circuit before releasing the short bar of the SRS-ECU
connector in the following operation.
DCable bands between terminals 29, 30 and the short bar
(width:3 mm, thickness:0.5 mm) between terminals 11 and
12 and the short bar, and release the short bar.
(See Figure A.)
Caution
As the short bar may not be releasable if inserted
insufficiently, insert more than 4 mm.
DMeasure at the harness side
DContinuity check between terminals 29 and 30
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 continuityResistor harness
(MB991866) Dummy resistor (MB991865)
resistance (3Ω)
Instrumental panel
wiring harness
Connector C-41NG
Figure A
Terminal
Short bar
Front view of SRS-ECU
connector C-41
(harness side)
Cable
band and etc.Section
A-A
4 mm or more
A
A
NOTE
*1: L.H. drive vehicles
*2: R.H. drive vehicles

SRS -Troubleshooting52B-25
Code No.27 Driver’s seat belt pre-tensioner (squib)
systemPossible Cause
This code is output when open circuit occurs in the SRS-ECU driver’s seat belt
pre-tensioner (squib) circuit.
However, SRS warning lamp goes out when a normal operation is resumed
(diagnosis code is not cleared.)DConnector improper contact
DOpen in the driver’s seat pre-tensioner (squib)
circuit
DSRS-ECU inoperable

MUT-II self-diag code
DConnect the dummy harness (MB991865) to the resistor harness
(MB991866).
DDisconnect the driver’s seat belt pre-tensioner connector D-28*
1and
D-26*2and insert the resistor harness (MB991866) behind the harness
side connector.
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.
DConnect the negative ( - ) terminal of the battery
DCheck the diagnosis code again after erasing the memory.
Is code No.27 output?
YESNO
Replace the driver’s seat belt pre-tensioner.
Replace the SRS-ECU.
Check the trouble
symptoms.
NG
Check the harness between the driver’s seat belt pre-tensioner
and the SRS-ECU, and repair if necessary. NG
OK
OKNG
Correct
Check connector:D-28*1,D-26*2, C-133*1, C-112*2, C-124 Driver’s seat belt
pre-tensioner connector
seat belt pretensioner>
Measure at the SRS-ECU connector C-41, the driver’s seat
belt pre-tensioner connector D-28*
1and D-26*2.
DDisconnect the SRS-ECU connector C-41 , the driver’s
seat belt pre-tensioner connector D-28*1and D-26*2, and
then measure at the harness side.
DContinuity check between the following terminals
Connector C-41 D-28*
1,D-26*2
29 – 2
30 – 1
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 (2Ωor less)Resistor harness
(MB991866) Dummy resistor
(MB991865)
resistance (3Ω)
Instrumental panel
wiring harness
Connector C-41D-28*
1,D-26*2connector
NOTE
*1: L.H. drive vehicles
*2: R.H. drive vehicles

SRS -Troubleshooting52B-26
Code No.28 Front passenger’s seat belt pre-tensioner
(squib) systemPossible Cause
This code is output when short circuit occurs between terminals of the
SRS-ECU front passenger’s seat belt pre-tensioner (squib) circuit.
However, SRS warning lamp goes out when a normal operation is resumed
(diagnosis code is not cleared.)DConnector engagement faulty or short bar faulty*
DShort circuit between terminals of the front
passenger’s seat belt pre-tensioner (squib) circuit
DFaulty connector
DSRS-ECU inoperable
NOTE
*: The connector of the squib circuit contains a short bar (short-circuiting the positive (+) cable and the
negative ( - ) cable to avoid an erroneous deployment caused by static electricity when a connector is
not connected). Thus, when a connector is connected, the short bar may not be released due to improper
engagement of the connector or faulty connector as shown in the illustration below. Disconnect the connector
as shown in the illustration below, then reconnect it. Check that a diagnosis code is output again after
erasing the memory. If the diagnosis code is not output, the above-mentioned code is output due to
improper engagement of the connector.
C-41C-133*1,
C-112*2D-28*1,
D-26*2
SRS-ECUFront passenger’s seat
belt pre-tensioner
NOTE
*1: L.H. drive vehicles
*2: R.H. drive vehicles