1999 MITSUBISHI LANCER EVOLUTION VI warning

SRS – Troubleshooting52B-12
Code No.43 SRS warning lamp drive circuit system
(Lamp does not illuminate.)Probable cause
This diagnosis code is output when an open circuit occurs for a continuous period
of 5 seconds while the SRS-ECU in monitoring the SRS warning lamp and the lamp
is OFF (transistor OFF).
However, if this code is output due to an open circuit, if the vehicle condition returns
to normal, this diagnosis code No.43 will be automatically erased, and the SRS warning
lamp will return to normal.
Malfunction of wiring harnesses or connectors

Blown bulb

Malfunction of SRS-ECU

Malfunction of combination meter
OK
Replace the combination
meter.
NG
Check the harness wire
between the SRS-ECU
and ignition switch (IG
1).NG
Repair
OK
Check trouble symptoms.
OK
Check the following
connectors:
B-51, B-09, B-08, B-75,
B-76NG
Repair
NG
Check the harness wire between the SRS-ECU and earth, and
repair if necessary.
OK
Check trouble symptoms.
Measure at SRS check harness
connector (5).

Disconnect SRS-ECU
connector B-51.

Connect SRS check
harness connector (3).

Continuity between
terminals (20)
OK:ContinuityNGCheck the following
connectors:
B-51, B-78, B-80NG
Repair
OK
Measure at SRS check harness connector (5).

Disconnect SRS-ECU connector B-51.

Connect SRS check harness connector (3).

Ignition switch: ON

Connect terminal (15) to the body earth.
OK:Lamp illuminatesNGBlown bulb inspectionNG
Repair
OK
Replace the SRS-ECU.
SRS check harness
(MB991613)
3
5
Code No.43 SRS warning lamp drive circuit system
(Lamp does not switch off.)
Probable cause
This diagnosis code is output when a short to earth occurs in the harness between
the lamp and the SRS-ECU while SRS-ECU is monitoring the SRS warning lamp
and the lamp is ON.
Malfunction of wiring harnesses or connectors

Malfunction of SRS-ECU

Malfunction of combination meter
SRS warning lamp inspection

Ignition switch: ON

Does lamp switch off when SRS-ECU connector B-51 is
disconnected?NoCheck the following
connectors:
B-51, B-09NG
Repair
Ye s
Replace the SRS-ECU.
OK
Check trouble symptoms.
NG
Check the harness wire
between the SRS-ECU
and combination meter,
and repair if necessary.

SRS – Troubleshooting52B-13
Code No.44 SRS warning lamp drive circuit systemProbable cause
This diagnosis code is output when a short occurs in the lamp drive circuit or a
malfunction of the output transistor inside the SRS-ECU is detected while the SRS-ECU
is monitoring the SRS warning lamp drive circuit.
Malfunction of wiring harnesses or connectors

Malfunction of SRS-ECU
Check the SRS warning lamp drive circuit system.
(Refer to P.52B-12)OKReplace the SRS-ECU.
Code No.45 SRS-ECU non-volatile memory (EEPROM)
and A/D converter systemProbable cause
This diagnosis code is output if there is a malfunction in the SRS-ECU non-volatile
memory (EEPROM) and A/D converter.
Malfunction of SRS-ECU
Code No.Trouble symptom
45Non-volatile memory
(EEPROM)
Non-volatile memory (EEPROM) is abnormal.
Replace the SRS-ECU.
Code No.51 or 52 Driver’s side air bag module (squib
ignition drive circuit) systemProbable cause
This diagnosis code is output if a short (No.51) or an open circuit (No.52) is detected
in the circuit for the driver’s seat.
Malfunction of SRS-ECU
Code No.Trouble symptom
51Driver’s side air bag module
(squib ignition drive circuit)

Short circuit in the squib ignition drive circuit
52
(squib ignition drive circuit)

Open circuit in the squib ignition drive circuit
Replace the SRS-ECU.
Code No.54 or 55 Front passenger’s side air bag module
(squib ignition drive circuit) systemProbable cause
This diagnosis code is output if a short (No.54) or an open circuit (No.55) is detected
in the circuit for the passenger’s seat.
Malfunction of SRS-ECU
Code No.Trouble symptom
54Front passenger’s side air
bag module (squib ignition

Short circuit in the squib ignition drive circuit
55
bag module (squib ignition
drive circuit)
Open circuit in the squib ignition drive circuit
Replace the SRS-ECU.

SRS – Troubleshooting52B-14
SRS WARNING LAMP INSPECTION
1. Check to be sure that the SRS warning lamp illuminates
when the ignition switch is in the ON position.
2. Check to be sure that it illuminates for approximately
7 seconds and then switches off.
3. If the above is not the cause, inspect the diagnosis codes.
INSPECTION CHART FOR TROUBLE SYMPTOMS
Get an understanding of the trouble symptoms and check according to the inspection procedure chart.
Trouble symptomInspection procedure No.Reference page
Communication with
MUT-II is not possible.Communication with all systems is not
possible.152B-14
Communication is not possible with
SRS only.252B-15
When the ignition key is turned to “ON” (engine stopped), the
SRS warning lamp does not illuminate.Refer to diagnosis code No.43.52B-12
After the ignition switch is turned to ON, the SRS warning lamp
is still on after approximately 7 seconds have passed.Refer to diagnosis code No.43.52B-12
INSPECTION PROCEDURE FOR TROUBLE SYMPTOMS
Inspection Procedure 1
Communication with MUT-II is not possible. (Communica-
tion with all systems is not possible.)
Probable cause
The cause is probably a power supply system (including earth circuit) of the diagnosis
line.
Malfunction of connectors

Malfunction of wiring harness
Refer to GROUP 13A – Troubleshooting.
SRS warning lamp

SRS – Troubleshooting / SRS Maintenance52B-15
Inspection Procedure 2
Communication with MUT-II is not possible.
(Communication is not possible with SRS only.)
Probable cause
If communication is not possible with the SRS only, the cause is probably an open circuit
in the diagnosis output circuit of the SRS or in the power circuit (including earth circuit).
Malfunction of wiring harnesses or connectors

Malfunction of SRS-ECU
OK
Check trouble symptoms.
NG
Check the harness wire between the SRS-ECU and earth, and
repair if necessary.
OK
Check trouble symptoms.
NG
Check the harness wire between the SRS-ECU and ignition switch
IG
1, and repair if necessary.
Measure at SRS check harness
connector (5).

Disconnect SRS-ECU
connector B-51.

Connect SRS check
harness connector (3).

Continuity between
terminals (20)
OK:ContinuityNGCheck the following
connectors:
B-51, B-78, B-80NG
RepairSRS check harness
(MB991613)
3
5
OK
Replace the SRS-ECU.
OK
Check the harness wire between the SRS-ECU and diagnosis
connector.NG
Repair
OK
Measure at SRS check harness connector (5).

Disconnect SRS-ECU connector B-51.

Connect SRS check harness connector (3).

Ignition switch: ON

Voltage between terminal (13) and body earth
OK:9 V or more

Voltage between terminal (14) and body earth
OK:9 V or moreNGCheck the following
connectors:
B-51, B-78, B-76NG
Repair
SRS MAINTENANCE
The SRS must be inspected by an authorized dealer 10 years
after the date of vehicle registration.
SRS WARNING LAMP CHECK
Turn the ignition key to the “ON” position. Does the SRS
warning lamp illuminate for about 7 seconds, turn off and
then remain extinguished for at least 5 seconds? If yes, SRS
system is functioning properly. If no, consult page 52B-6.
SRS warning lamp

SRS – SRS Maintenance52B-18
BODY WIRING HARNESS
* Body wiring harness
NOTE
*: Vehicles with front passenger’s air bag
1. Check connector for poor connection.
2. Check harnesses for binds, connectors for damage, and
terminals for deformation.
REPLACE ANY CONNECTORS OR HARNESS THAT
FAIL THE VISUAL INSPECTION. (Refer to P.52B-3.)
Caution
The SRS may not activate if SRS harnesses or
connectors are damaged or improperly connected,
which could result in serious injury or death to the
vehicle’s driver or front passenger.
POST-INSTALLATION INSPECTION
Reconnect the negative battery terminal. Turn the ignition
key to the “ON” position. Does the SRS warning lamp illuminate
for about 7 seconds, turn off and then remain extinguished
for at least 5 seconds? If yes, SRS system is functioning
properly. If no, consult page 52B-6.
SRS warning lamp

SRS – Warning/Caution Labels52B-23
WARNING/CAUTION LABELS
A number of caution labels related to the SRS are
found in the vehicle, as shown in the followingillustration. Follow label instructions when servicing
SRS. If labels are dirty or damaged, replace them.
Steering wheel Air bag module (driver’s side) Clock spring
Glove box Sun visor SRS-ECU
Steering gear and linkage Air bag module
(front passenger’s side)

SRS – SRS-ECU / Air Bag Modules and Clock Spring52B-25
INSTALLATION SERVICE POINTS
ASRS-ECU INSTALLATION
Caution
The SRS may not activate if SRS-ECU is not installed
properly, which could result in serious injury or death
to the vehicle’s driver or front passenger.
BPOST-INSTALLATION INSPECTION
1. Reconnect the negative battery terminal.
2. Turn the ignition key to the “ON” position.
3. Does the “SRS” warning lamp illuminate for about 7
seconds, and then remain extinguished for at least 5
seconds after turning OFF?
4. If yes, SRS system is functioning properly.
If no, consult page 52B-6.
INSPECTION

Check the SRS-ECU and brackets for dents, cracks or
deformation.

Check connector for damage, and terminals for
deformation.
Caution
If a dent, crack, deformation or rust is discovered,
replace the SRS-ECU with a new one.
NOTE
For checking of the SRS-ECU other than described above,
refer to the section concerning troubleshooting. (Refer
to P.52B-6.)
AIR BAG MODULES AND CLOCK SPRING
Caution
1. Disconnect the battery (–) terminal and wait
for 60 seconds or more before starting work.
Furthermore, the disconnected battery
terminal should be covered with tape to
insulate it. (Refer to P.52B-3.)
2. Never attempt to disassemble or repair the
air bag modules or clock spring.
If faulty, replace it.
3. Do not drop the air bag modules or clock
spring or allow contact with water, grease
or oil.
Replace it if a dent, crack, deformation or
rust is detected.
4. The air bag modules should be stored on
a flat surface and placed so that the pad
surface is facing upward.
Do not place anything on top of it.5. Do not expose the air bag modules to
temperatures over 93C.
6. Both driver’s side and front passenger’s
side air bag modules should be replaced
with new ones once the respective air bags
were deployed. The clock springs should
also be checked and replaced with new ones
if considered abnormal.
7. Wear gloves and safety glasses when
handling air bags that have already
deployed.
8. An undeployed air bag module should only
be disposed of in accordance with the
procedures (Refer to P.52B-32.)
SRS warning lamp

SRS – Air Bag Modules and Clock Spring52B-29
BCLOCK SPRING INSTALLATION
Align the mating marks of the clock spring and, after turning
the front wheels to the straight-ahead position, install the
clock spring to the column switch.
Mating Mark Alignment
Turn the clock spring clockwise fully, and then turn back it
approx. 3 4/5 turns counterclockwise to align the mating marks.
Caution
If the clock spring’s mating marks are not properly aligned,
the steering wheel may not be completely rotational during
a turn, or the flat cable within the clock spring may be
severed, obstructing normal operation of the SRS and
possibly leading to serious injury to the vehicle’s driver.
CSTEERING WHEEL INSTALLATION
1. Before installation the steering wheel, be sure to first
turn the vehicle’s front wheels to the straight-ahead
position and align the mating marks of the clock spring.
Caution
Be sure when installing the steering wheel, that the
harness of the clock spring does not become caught
or tangled.
2. After clamping, turn the steering wheel all the way in
both directions to confirm that steering is normal.
DPOST-INSTALLATION INSPECTION
1. Turn the steering wheel lightly to the left and right to
check if it can be operated properly without any
abnormality.
2. Reconnect the negative battery terminal.
3. Turn the ignition key to the “ON” position.
4. Does the “SRS” warning lamp illuminate for about 7
seconds, and then remain extinguished for at least 5
seconds after turning OFF?
5. If yes, SRS system is functioning properly.
If no, consult page 52B-6.
Mating marks
SRS warning lamp