MITSUBISHI LANCER EVOLUTION VI 1999 Workshop Manual

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-16
SRS COMPONENT VISUAL CHECK
Turn the ignition key to the LOCK (OFF) position, disconnect
the negative battery cable and tape the terminal.
Caution
Wait at least 60 seconds after disconnecting the battery
cable before doing any further work. (Refer to P.52B-3.)
SRS CONTROL UNIT (SRS-ECU)
1. Check SRS-ECU case and brackets for dents, cracks,
deformation or rust.
Caution
The SRS may not activate if the SRS-ECU is not
installed properly, which could result in serious injury
or death to the vehicle’s driver or front passenger.
2. Check connector for damage, and terminals for
deformation or rust.
Replace SRS-ECU if it fails visual check.
(Refer to P.52B-24.)
AIR BAG MODULES, STEERING WHEEL AND CLOCK
SPRING
1. Remove the air bag modules, steering wheel and clock
spring. (Refer to P.52B-25.)
Caution
The removed air bag modules should be stored in
a clean, dry place with the pad cover face up.
2. Check pad cover for dents, cracks or deformation.
Insulating tape
Battery
Battery (–) cable
SRS-ECU
Pad cover


Pad cover

SRS – SRS Maintenance52B-17
3. Check connector for damage, terminals deformities, and
harness for binds.
4. Check air bag inflator case for dents, cracks or deformities.
5. Check harness and connectors for damage, and terminals
for deformation.
6. Check clock spring connectors and protective tube for
damage, and terminals for deformation.
7. Visually check the clock spring case for damage.
8. Align the mating marks of the clock spring and, after
turning the vehicle’s front wheels to 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 mark is 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 or front passenger.
9. Install the steering column covers, steering wheel and
the air bag module.
10. Check steering wheel for noise, binds of difficult operation.
11. Check steering wheel for excessive free play.
REPLACE ANY VISUALLY INSPECTED PART IF IT
FAILS THAT INSPECTION. (Refer to P.52B-25.)
Caution
The SRS may not activate if any of the above
components is not installed properly, which could
result in serious injury or death to the vehicle’s driver
or front passenger.
Inflator case
Connector

Inflator case
Connector
Protective tube
Case
Mating marksProtective tube

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 – Post-collision Diagnosis52B-19
POST-COLLISION DIAGNOSIS
To inspect and service the SRS after a collision (whether
or not the air bags have deployed), perform the following
steps.
SRS-ECU MEMORY CHECK
1. Connect the MUT-II to the diagnosis connector (16-pin).
Caution
Make certain that the ignition switch is OFF when
the MUT-II is connected or disconnected.
2. Read (and write down) all displayed diagnosis codes.
(Refer to P.52B-6.)
NOTE
If the battery power supply has been disconnected or
disrupted by the collision, the MUT-II cannot communicate
with the SRS-ECU. Inspect and, if necessary, repair the
body wiring harness before proceeding further.
3. Read the data list (fault duration and how many times
memories are erased) using the MUT-II.
Data list
NoService Data ItemApplicability
92Number indicating houw often the memory is clearedMaximum time to be stored: 250
93How long a problem has lasted (How long it takes
from the occurrence of the problem till the first igniting
signal)Maximum time to be stored: 9,999 minutes
(approximately 7 days)
94How long a problem has lasted (How long it takes
from the first igniting signal till now)
4. Erase the diagnosis codes and after waiting 5 seconds
or more read (and write down) all displayed diagnosis
codes. (Refer to P.52B-6.)

SRS – Post-collision Diagnosis52B-20
REPAIR PROCEDURE
WHEN AIR BAG DEPLOYS IN A COLLISION.
1. Replace the following parts with new ones.

SRS-ECU (Refer to P.52B-24.)

Air bag module (Refer to P.52B-25.)
2. Check the following parts and replace if there are any
malfunctions.

Clock spring (Refer to P.52B-25.)

Steering wheel, steering column and intermediate
joint
(1) Check wiring harness (built into steering wheel)
and connectors for damage, and terminals for
deformation.
(2) Install air bag module to check fit or alignment
with steering wheel.
(3) Check steering wheel for noise, binds or difficult
operation and excessive free play.
3. Check harnesses for binding, connectors for damage,
poor connections, and terminals for deformation.
(Refer to P.52B-18.)
WHEN AIR BAG DOES NOT DEPLOY IN LOW-SPEED
COLLISION.
Check the SRS components. If the SRS components are
showing any visible damage such as dents, cracks, or
deformation, replace them with new ones. Concerning parts
removed for inspection, replacement with new parts and
cautionary points for working, refer to appropriate INDIVIDUAL
COMPONENT SERVICE, P.52B-22.

SRS – Post-collision Diagnosis52B-21
SRS-ECU
1. Check SRS-ECU case and brackets for dents, cracks
or deformation.
2. Check connector for damage, and terminals for
deformation.
Air bag modules
1. Check pad cover for dents, cracks or deformation.
2. Check connector for damage, terminals deformities, and
harness for binds.
3. Check air bag inflator case for dents, cracks or deformities.
4. Install air bag module to steering wheel to check fit or
alignment with the wheel.
Clock spring
1. Check clock spring connectors and protective tube for
damage, and terminals for deformation.
2. Visually check the case for damage.
SRS-ECU

Connector

Inflator case
ConnectorInflator case
Case Protective tube
Protective tube

SRS – Post-collision Diagnosis / Individual Component Service52B-22
Steering wheel, steering column and intermediate joint
1. Check wiring harness (built into steering wheel) and
connectors for damage, and terminals for deformation.
2. Install air bag module to check fit or alignment with steering
wheel.
3. Check steering wheel for noise, binds or difficult operation
and excessive free play.
Harness connector (body wiring harness)
Check harnesses for binding, connectors for damage, poor
connection, and terminals for deformation. (Refer to P.52B-18.)
INDIVIDUAL COMPONENT SERVICE
If the SRS components are to be removed or replaced as a result of maintenance, troubleshooting,
etc., follow each procedure (P.52B-24 – P.52B-31)
Caution
1. SRS components should not be subjected to hear over 93C, so remove the SRS-ECU, air
bag module and clock spring before drying or baking the vehicle after painting.
Recheck SRS system operability after re-installing them.
2. If the SRS components are removed for the purpose of check, sheet metal repair, painting,
etc., they should be stored in a clean, dry place until they are reinstalled.

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-ECU52B-24
SRS AIR BAG CONTROL UNIT (SRS-ECU)
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
SRS-ECU. If faulty, replace it.3. Do not drop or subject the SRS-ECU to
impact or vibration.
If denting, cracking, deformation, or rust
are discovered in the SRS-ECU, replace it
with a new SRS-ECU. Discard the old one.
4. After deployment of an air bag, replace the
SRS-ECU with a new one.
REMOVAL AND INSTALLATION
Pre-removal Operation

Turn the ignition key to the LOCK (OFF) position.

Negative (–) battery cable connection
1
4.9 Nm
Removal steps

Floor console
1. SRS-ECUInstallation steps
B
Post-installation inspection

Negative (–) battery cable connection
A1. SRS-ECU

Floor console