2007 MITSUBISHI LANCER EVOLUTION Service Repair Manual

SRS -Special Tools52B-5
SPECIAL TOOLS
ToolNumberNameUse
MB991502MUT-IIsub
assemblyDReading and erasing diagnosis codes
DReading trouble period
DReading erase times
MB991865Dummy resistorChecking SRS air bag circuit
MB991866Resistor harness
MB991613SRS check
harnessChecking SRS electrical circuitry
A
B
C
DMB991223
A: MB991219
B: MB991220
C: MB991221
D: MB991222Harness set
A: Check harness
B: LED harness
C: LED harness
adapter
D: ProbeChecking continuity and measuring voltage at
SRS-ECU harness connector
MB990803Steering wheel
pullerRemoving steering wheel
MR372530SRS air bag
adapter harnessDeploying driver’s air bag module inside
vehicle

SRS -Special Tools/Test Equipment/Troubleshooting52B-6
Tool UseName Number
MB686560SRS air bag
adapter harnessDeploying front passenger’s air bag module
inside or outside vehicle
MR203491or
MB628919SRS air bag
adapter harnessDeploying driver’s air bag module inside
vehicle
TEST EQUIPMENT
ToolNameUse
Digital multi-meterChecking SRS electrical circuitry
Use multi-meter for which the maximum test
current is 2 mA or less at minimum range of
resistance measurement
TROUBLESHOOTING
STANDARD FLOW OF DIAGNOSTIC TROUBLESHOOTING
Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points.
DIAGNOSIS FUNCTION
DIAGNOSIS CODES CHECK
Connect the MUT-IIto the diagnosis connector (16-pin) under the instrument under cover, then check
diagnosis codes.
(Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points.)
ERASING DIAGNOSIS CODE
Connect the MUT-IIto the diagnosis connector and erase the diagnosis code.
Caution
Turn off the ignition switch before connecting or disconnecting the MUT-II.
SRS WARNING LAMP CHECK
1. Check that the SRS warning lamp comes on when the
ignition switch is turned ON.
2. Check that the SRS warning lamp illuminates for about
7 seconds and then goes out.
3. If this is not the cause, check the diagnosis codes.
SRS warning lamp

SRS -Troubleshooting52B-7
SRS SYSTEM CIRCUIT DIAGRAM
Ignition switch (IG1)
J/B
(common fuse)
Combination
Meter
Connector lock switch*
ON
ON OFF
OFF
Driver’s air
bag module
(squib)
Front pas-
senger’s seat
air bag mod-
ule(squib)
Seat belt
pre-tensioner
(L.H.)Clock spring
ONONOFF
OFF
Connector lock switch* Diagnosis connector SRS-ECU
No.3
7.5A No.2
7.5A
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFFON
ON
ON
ON
ON
ON
ON
ONOFF
ON
ON OFF
C-207
C-204
C-109
D-28
D-26C-22
SRS - ECU connector16
13
7 8
11
12
10
9
30
29
28
2720 Connector lock switch*
Connector lock switch*
Connector lock switch*
Connector lock switch*
Connector lock switch*
NOTE
*:connector engaged:ON
connector disengaged:OFF Seat belt
pre-tensioner
(R.H.)

SRS -Troubleshooting52B-8
CONNECTOR FOR SRS AIR BAG
The SRS air bag system connector is yellow or red.
To enhance system reliability, a connector lock switch is adopted for the SRS-ECU connector, and each
air bag module and clock spring connector, each seat belt with pre-tensioner following illustration (black)>).
AClock
spring
SRS-ECUDriver’s air bag module
Front passenger’s air bag module A
A ADriver’s seat belt pre-tensioner
Front passenger’s seat belt pre-tensioner
SQUIB CIRCUIT CONNECTOR LOCK SWITCH
Mechanism to automatically short-circuit the power supply terminal and the earth terminal of the air bag squib
circuit when the connector is disconnected. The short spring inside the connector allows to short-circuit the
power supply terminal and the earth terminal of the squib (no difference in voltage occurs between the
terminals) to prevent the squib from getting charged with static electricity.
CAUTION
When the connector is disconnected, it is normal for short-circuiting to occur between the connector
terminals.
When connector is connected
When connector is disconnectedOFF
ON
OFFOFF
OFF
ONON
ON
ECU side connectorHarness side connector
A A
Short spring
Partition panelTerminal
(Female) Terminal
(Male)B
BSection A - A
Section B - B
Partition
panelShort springTerminal
(Female)
Terminal
(Male)When connector is connected
Partition panel
Terminal
(Female) Te r m i n a l
(Male) SquibSquib
SRS-ECUSRS-ECU
Short spring

SRS -Troubleshooting52B-9
WARNING LAMP CIRCUIT CONNECTOR LOCK SWITCH
Mechanism to automatically short-circuit the power supply
terminal and the earth terminal of the warning lamp circuit
when the SRS-ECU connector is disconnected. The structure
is the same as that of squib circuit connector lock switch.
INSPECTION CHART FOR DIAGNOSIS CODES
Inspect according to the inspection chart that is appropriate for the malfunction code.
Code no.Diagnostic itemPage
14SRS-ECU front impact analog G-sensor system52B-11
15SRS-ECU front impact safing G-sensor systemShort circuit in the
sensor52B-11
16SRS-ECU front impact safing G-sensor systemOpen circuit in the
sensor
21*1Driver’s air bag module (squib) systemShort circuit between
terminals of the squib
circuit52B-12
22*1Driver’s air bag module (squib) systemOpen in the squib
circuit52B-16
24*1Front passenger’s air bag module (squib) systemShort circuit between
terminals of the squib
circuit52B-20
25*1Front passenger’s air bag module (squib) systemOpen in the squib
circuit52B-22
26*1Driver’s seat belt pre-tensioner (squib) systemShort circuit between
terminals of the squib
circuit52B-23
27*1Driver’s seat belt pre-tensioner (squib) systemOpen in the squib
circuit52B-25
28*1Front passenger’s seat belt pre-tensioner (squib) systemShort circuit between
terminals of the squib
circuit52B-26
29*1Front passenger’s seat belt pre-tensioner (squib) system/Open in the squib
circuit52B-28
31SRS-ECU DC-DC converter systemIncreased terminal
voltage52B-11
32SRS-ECU DC-DC converter systemDecreased terminal
voltage
Ignition switch (IG1)
SRS warning lamp
SRS-ECU harness
side connector
Short spring
ON
ONOFF
OFF Connector*
lock switch
NOTE
*:connector engaged:ON
connector disengaged:OFF

SRS -Troubleshooting52B-10
Code no.Page Diagnostic item
34*2Connector lock system52B-29
35SRS-ECU (deployed air bag) system52B-29
41*2Power supply circuit system (fuse No.2 circuit)52B-30
42*2Power supply circuit system (fuse No.3 circuit)52B-32
43*2SRS warning lamp drive circuit systemLamp does not illumi-
nate.52B-33
SRS warning lamp drive circuit systemLamp does not go out.52B-33
44*2SRS warning lamp drive circuit system52B-33
45SRS-EUC internal circuit system including non - volatile memory (EEPROM)52B-11
51Driver’s air bag module (squib) ignition drive circuit systemShort in the ignition
drive circuit52B-11
52Driver’s air bag module (squib) ignition drive circuit systemOpen in the ignition
drive circuit
54Front passenger’s air bag (squib) ignition drive circuit
systemShort in the ignition
drive circuit52B-11
55Front passenger’s air bag (squib) ignition drive circuit
systemOpen in the ignition
drive circuit
56Driver’s seat belt pre-tensioner (squib) ignition drive circuit
systemShort in the ignition
drive circuit52B-11
57Driver’s seat belt pre-tensioner (squib) ignition drive circuit
systemOpen in the ignition
drive circuit
58Front passenger’s seat belt pre-tensioner (squib) ignition
drive circuit systemShort in the ignition
drive circuit52B-11
59Front passenger’s seat belt pre-tensioner (squib) ignition
drive circuit systemOpen in the ignition
drive circuit
61Driver’s air bag module (squib) systemShort-circuited to
power supply52B-34
62Driver’s air bag module (squib) systemShort-circuited to earth
64Front passenger’s air bag module (squib) systemShort-circuited to
power supply52B-38
65Front passenger’s air bag module (squib) systemShort-circuited to earth
66Driver’s seat belt pre-tensioner (squib) systemShort-circuited to
power supply52B-39
67Driver’s seat belt pre-tensioner (squib) systemShort-circuited to earth
68Front passenger’s seat belt pre-tensioner (squib) systemShort-circuited to
power supply52B-40
69Front passenger’s seat belt pre-tensioner (squib) systemShort-circuited to earth
NOTE
(1) *1: If the trouble(s) are removed, the SRS warning lamp go out with diagnosis code history stored.
(2) *2: If the trouble(s) are removed, the SRS warning lamp will go out with diagnosis code history automatically erased.
(3) When the battery has been discharged, diagnosis code No.41 or 42 is stored. Check the battery when either of
these is displayed.

SRS -Troubleshooting52B-11
INSPECTION PROCEDURE CLASSIFIED BY DIAGNOSIS CODE
Code No.14, 15, 16, 31, 32, 45, 51, 52, 54, 55, 56, 57, 58, 59
System inside SRS-ECUProbable cause
Malfunction is present inside SRS-ECU. See table below for what each code
tells.DMalfunction of SRS-ECU
Code No.Defective partsTrouble
14Front impact analog G-sensorDNot operating
DAbnormal characteristics
DAbnormal output
15Front impact safing G-sensorDShort in the circuit
16DOpen in the circuit
31DC-DC converterDTerminal voltage of the converter higher than specified for
five seconds or more
32DTerminal voltage of the converter lower than specified for
5 seconds or more (this code is not detected when code
No.41 or 42, which indicates discharged battery, has been
detected)
45Non-volatile memory (EEPROM)DDefective parts inside
51Driver’sairbagmodule(squib)DShortinthecircuit51Driver’sairbag module(squib)
ignitiondrivecircuit
DShortinthecircuit
52ignition drive circuitDOpen in the circuit
54Front passenger’s air bag module
(squib)ignitiondrivecircuit
DShort in the circuit
55(squib)ignitiondrive circuitDOpen in the circuit
56Driver’s seat belt pre-tensioner
(squib)ignitiondrivecircuit
DShort in the circuit
57(squib)ignitiondrive circuitDOpen in the circuit
58Front passenger’s seat belt pre-ten-
sioner(squib)ignitiondrivecircuit
DShort in the circuit
59sioner(squib)ignitiondrive circuitDOpen in the circuit
If the above - mentioned code No. is output, replace the SRS-ECU.

SRS -Troubleshooting52B-12
Code No.21 Driver’s air bag module (squib) systemPossible Cause
This code is output when short circuit occurs between terminals of the
SRS-ECU driver’s air bag module (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 in the clock spring
DShort circuit between terminals of the driver’s air
bag module (squib) circuit
DFaulty connector
DSRS-ECU inoperable
NOTE:
(1) *: 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-204C-207
SRS-ECU
Clock spring
Driver’s air bag module C-21
(2) Two different types of driver’s air bag modules by model are featured. Thus, two types of air bag
module by model are described in the following flowchart.
RS: Steering wheel and air bag module separate type
RS-II: Steering wheel and air bag module incorporate type