Mitsubishi Grandis. Manual — part 1036
TROUBLESHOOTING
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
52B-196
CAUTION
If diagnosis code B1570, B1571, B1572, B1573,
B1574, B1575, B1576, B1577, B1578, B1579 or
B1581 are set in the SRS-ECU, always diagnose
the CAN bus lines.
OPERATION
According to the passenger’s air bag cut off switch
connecting position, the SRS-ECU judges the
deployment and non-deployment of passenger’s
(front) air bag.
DIAGNOSIS CODE SET CONDITIONS
Diagnosis code is set when the resistance between
input terminals of the passenger’s air bag cut off
switch in the SRS-ECU is without the standard value.
Cause of trouble in each diagnosis code is as
follows.
PROBABLE CAUSES
• Malfunction of the passenger’s air bag cut off
switch
• Damaged wiring harnesses or connectors
• Malfunction of the SRS-ECU
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 3.
NO :
Repair the CAN bus line (Refer to GROUP
54D, Diagnosis
). Then go to Step
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
).
Code No.
Symptom
B1570
Malfunction of passenger’s air bag cut off switch
B1571
Malfunction of the Normal/Close terminal or short circuit in its harness
B1572
Short to body earth in the Normal/Close terminal harness
B1573
Short to the power supply in the Normal/Close terminal harness
B1574
Malfunction of the Normal/Open terminal or short circuit in its harness
B1575
Short to body earth in the Normal/Open terminal harness
B1576
Short to the power supply in the Normal/Open terminal harness
B1577
Malfunction of the COM terminal or short circuit in its harness
B1578
Short to body earth in the COM terminal harness
B1579
Short to the power supply in the COM terminal harness
B1581
Detection of passenger’s air bag cut off switch misconecton
TROUBLESHOOTING
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
52B-197
STEP 3. Connector check: C-107 passenger’s air
bag cut off switch connector
Q: Is the check result normal?
YES :
Go to Step 4.
NO :
Repair the defective connector.
STEP 4. Check the passenger’s air bag cut off
switch.
Refer to
Q: Is the check result normal?
YES :
Go to Step 5.
NO :
Replace passenger’s air bag cut off switch.
(Refer to
STEP 5. Check the passenger’s air bag cut off
switch circuit. Resistance measurement at
SRS-ECU connector C-119.
(1) Disconnect SRS-ECU connector C-119.
CAUTION
Do not insert a test probe into the terminal from
its front side directly as the connector contact
pressure may be weakened.
(2) Measure the resistance between terminal 29 and
terminal 35.
OK: Less than 10m
Ω
(3) Switch the passenger’s air bag cut off switch to
AC311374AB
Connector: C-107 <LHD>
Harness side
(front view)
AC311376AB
Connector: C-107 <RHD>
Harness side
(front view)
AC311438 AD
C-119 (Y)
Connector: C-119
Harness side
(front view)
AC313360
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)
AB
AC313364
PASSENGER
AIRBAG
ON
OFF
AB
TROUBLESHOOTING
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
52B-198
air bag OFF side.
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 resistance between terminal 41 and
terminal 35.
OK: Less than 10m
Ω
Q: Is the check result normal?
YES :
Go to Step 6.
NO :
Repair the harness wires between
SRS-ECU connector C-119 (terminal No.29,
35 and 41) and passenger’s air bag cut off
switch connector C-107 (terminal No.1, 2
and 4).
STEP 6. Check whether the diagnosis code is
reset.
Q: Is diagnosis code B1570, B1571, B1572, B1573,
B1574, B1575, B1576, B1577, B1578, B1579 or
B1581 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
).
Code No.U1073: Bus Off
CAUTION
If diagnosis code U1073 is set in the SRS-ECU,
diagnose the CAN main bus line.
CAUTION
Whenever the ECU is replaced, ensure that the
input and output signal circuits are normal.
TROUBLE JUDGMENT
Diagnosis code No.U1073 will be stored when the
SRS-ECU ceases CAN communication (bus off) and
then resumes the communication by turning the
ignition switch to the "LOCK" (OFF) position
COMMENTS ON TROUBLE SYMPTOM
The wiring harness wire or connectors may have
loose, corroded, or damage terminals, or terminals
pushed back in the connector, or the SRS-ECU may
be defective.
PROBABLE CAUSES
• Defective connector(s) or wiring harness
• Malfunction of the SRS-ECU
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 check result satisfactory?
YES :
There is an intermittent malfunction such as
poor engaged connector(s) or open circuit
(Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service
Points
NO :
Replace the SRS-ECU. On completion,
check that the diagnosis code is not reset.
AC313361
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)
AB
TROUBLESHOOTING
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
52B-199
CHECK CHART FOR TROUBLE
SYMPTOMS
M1524003400600
Trouble
Inspection procedure No.
Reference page
Communication between the MUT-III and the
SRS-ECU is not possible.
1
Power supply circuit system
2
When the ignition switch is turned to the "ON"
position (engine stopped), the SRS warning
lamp does not illuminate.
3
After the ignition switch is turned to the "ON"
position, the SRS warning lamp does not go off
within approximately seven seconds.
4
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст