Mitsubishi Grandis. Manual — part 1026
TROUBLESHOOTING
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
52B-156
STEP 4. Check the driver's seat belt
pre-tensioner circuit. Voltage measurement at the
SRS-ECU connector C-120.
(1) Disconnect SRS-ECU connector C-120.
(2) Disconnect seat belt pre-tensioner (LH)
connector D-19. Use a flat-tipped screwdriver to
unlock the locking button at the harness side
connector by with drawing it toward you in two
stages, and then disconnect the connector.
(3) Turn the ignition switch to the "ON" position.
CAUTION
Do not insert a test probe into the terminal from
its front side directly, as the connector contact
pressure may be weakened.
(4) Measure the voltage between C-120 harness
side connector terminals 7, 8 and body earth.
OK: 0 V
Q: Is the check result normal?
YES :
Go to Step 5.
NO :
Repair the harness wires between
SRS-ECU connector C-120 (terminal No.7
and 8) and seat belt pre-tensioner (LH)
connector D-19 (terminal No.1 and 2).
STEP 5. Check whether the diagnosis code is
reset.
Q: Is diagnosis code B1473 set?
YES :
Replace the SRS-ECU (Refer
to
NO :
An intermittent malfunction is suspected
(Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points
).
AC311438 AE
C-120 (Y)
Connector: C-120
Harness side
(front view)
AC302393AC
D-19 (B)
Connector: D-19
Centre
pillar
Front vehicle
Harness side
(front view)
AC103556 AY
Locking button
Flat-tip screw
driver
D-19 Harness
side connector
D-19 Seat belt
pre-tensioner (LH)
connector
AC308187
A
B
18
10
15
7
13
5
14
6
16
8
17
9
19
11
20
12
1 2
3 4
C-120 Harness side
connector (rear view)
AD
TROUBLESHOOTING
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
52B-157
Code No.B1476: IG1 Power Supply Circuit System (Fuse No.2 Circuit) Code No.B1477: IG1 Power
Supply Circuit System (Fuse No.3 Circuit)
Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Gray R : Red P : Pink V : Violet
IGNITION
SWITCH (IG1)
SRS-ECU
IG1 Power Supply Circuit <LH drive vehicles>
TROUBLESHOOTING
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
52B-158
CAUTION
If diagnosis code B1476 <Fuse No.2> or B1477
<Fuse No.3> is set in the combination meter,
always diagnose the CAN bus lines.
OPERATION
• The SRS-ECU is powered from the ignition
switch (IG1).
• The SRS-ECU power is supplied from two
circuits. Even if one circuit is shut off, the air bag
can inflate.
DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set if the voltage between the
IG1 terminals (fuse No.2 circuit or fuse No.3 circuit)
and earth is lower than a predetermined value for a
continuous period of 5 second or more. However, if
the vehicle condition returns to normal, diagnosis
code number B1476 <Fuse No.2> or B1477 <Fuse
No.3> will be automatically erased, and the SRS
warning light will switch off.
PROBABLE CAUSES
• Damaged wiring harnesses or connectors
• Malfunction of the SRS-ECU
Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Gray R : Red P : Pink V : Violet
IGNITION
SWITCH (IG1)
SRS-ECU
IG1 Power Supply Circuit <RH drive vehicles>
TROUBLESHOOTING
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
52B-159
DIAGNOSIS PROCEDURE
STEP 1. MUT-III CAN bus diagnostics
Use the MUT-III to diagnose the CAN bus lines.
Q: Is the check result normal?
YES :
Go to Step 2.
NO :
Repair the CAN bus line (Refer to GROUP
54D, Diagnosis
STEP 2. Check whether the diagnosis code is
reset.
Check again if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition: LOCK (OFF) position to ON
(3) On completion, check that the diagnosis code is
not reset.
Q: Is the diagnosis code set?
YES :
Go to Step 3.
NO :
There is an intermittent malfunction such as
poor engaged connector(s) or open circuit
(Refer to GROUP 00, How to Cope with
Intermittent Malfunction
STEP 3. Check junction block fuse number 2
<B1476> or 3 <B1477>.
Q: Is the fuse burned out?
YES :
Go to Step 6.
NO :
Go to Step 4.
STEP 4. Check the power supply circuit for open
circuit. Voltage measurement at SRS-ECU
connector C-119.
(1) Disconnect the negative battery terminal.
(2) Disconnect SRS-ECU connector C-119.
(3) Connect the negative battery terminal.
(4) Turn the ignition switch to the "ON" position.
CAUTION
Do not insert a test probe into the terminal from
its front side directly, as the connector contact
pressure may be weakened.
(5) Measure the voltage between C-119 harness
side connector terminal 24 <B1476> or 23
<B1477> and body earth.
OK: 9 V or more.
Q: Is the measured voltage within the specified
range?
YES :
Erase the diagnosis connector memory, and
check the diagnosis code. If diagnosis code
B1476 or B1477 set, replace the SRS-ECU.
(Refer to
). Then go to Step 10.
NO :
Go to Step 5.
AC309960AC
FUSE No. 3
JUNCTION
BLOCK
FUSE No. 2
<LHD>
AC302449
AC309956AC
FUSE No. 3
JUNCTION
BLOCK
FUSE No. 2
<RHD>
AC311438 AD
C-119 (Y)
Connector: C-119
Harness side
(front view)
AC308202
42
31
38
27
21
41
28
39
22
30
25
47
36
33
44
34
45
37
48
26
29
23
40
32
43
35
46
24
B
A
C-119 Harness side
connector (rear view)
AD
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст