SRS-8
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionEHS0016M
CAUTION:
Do not use electrical test equipment on any circuit related to the SRS unless instructed to do so in
this Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harness con-
nectors.
Do not attempt to repair, splice or modify SRS wiring harnesses. If a harness is damaged, replace
it with a new one.
Keep ground connections clean.
DIAGNOSIS FUNCTION
The SRS self-diagnosis results can be read by using “AIR BAG” warning lamp and/or CONSULT-II.
The User mode is exclusively prepared for the customer (driver). This mode warns the driver of a system mal-
function through the operation of the “AIR BAG” warning lamp.
The Diagnosis mode allows the technician to locate and inspect the malfunctioning part.
The mode applications for the “AIR BAG” warning lamp and CONSULT-II are as follows:
HOW TO PERFORM TROUBLE DIAGNOSES FOR QUICK AND ACCURATE REPAIR
A good understanding of the malfunction conditions can make troubleshooting faster and more accurate.
In general, each customer feels differently about a malfunction. It is important to fully understand the symp-
toms or conditions for a customer complaint.
Information From Customer
WHAT - Vehicle model
WHEN - Date, Frequencies
WHERE - Road conditions
HOW - Operating conditions, Symptoms
Preliminary Check
Check that the following parts are in good order.
Battery (Refer to SC-4, "How to Handle Battery" .)
Fuse (Refer to SRS-12, "Wiring Diagram— SRS —" .)
System component-to-harness connections
User mode Diagnosis mode Display type
“AIR BAG” warning lamp X X ON-OFF operation
CONSULT-II — X Monitoring
SRS-18
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
CONSULT-II Function (AIR BAG)EHS001BA
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
CONSULT-II FunctionEHS0016Q
HOW TO CHANGE SELF-DIAGNOSIS MODE WITH CONSULT-II
From User Mode to Diagnosis Mode
After selecting “AIR BAG” on the “SELECT SYSTEM” screen, User mode automatically changes to Diagnosis
mode.
From Diagnosis Mode to User Mode
To return to User mode from Diagnosis mode, touch “BACK” key of CONSULT-II until “SELECT SYSTEM”
appears, Diagnosis mode automatically changes to User mode.
AIR BAG diagnostic mode Description
SELF-DIAG [CURRENT]A current Self-diagnosis result (also indicated by the number of warning lamp flashes in the Diagnosis
mode) is displayed on the CONSULT-II screen in real time. This refers to a malfunctioning part requir-
ing repairs.
SELF-DIAG [PAST]Diagnosis results previously stored in the memory are displayed on the CONSULT-II screen. The
stored results will remain until memory erasing is executed.
TROUBLE DIAG RECORDWith TROUBLE DIAG RECORD, diagnosis results previously erased by a reset operation can be dis-
played on the CONSULT-II screen.
ECU DISCRIMINATED NO.The air bag diagnosis sensor unit for each vehicle
model is assigned with its own, individual classifi-
cation number. This number will be displayed on
the CONSULT-II screen, as shown. When replac-
ing the air bag diagnosis sensor unit, refer to the
part number for the compatibility. After installation,
replacement with a correct unit can be checked by
confirming this classification number on the CON-
SULT-II screen.
For INFINITI MODEL JA60, the air bag diagno-
sis sensor unit discriminated number assigned
is F62B.
ARS3 66
SRS8 03
SRS8 04
TROUBLE DIAGNOSIS
SRS-19
C
D
E
F
G
I
J
K
L
MA
B
SRS
Revision: October 20052005 QX56
HOW TO ERASE SELF-DIAGNOSIS RESULTS
“SELF-DIAG [CURRENT]”
A current self-diagnosis result is displayed on the CONSULT-II
screen in real time.
After the malfunction is repaired completely, no malfunction is
detected on “SELF-DIAG [CURRENT]”.
“SELF-DIAG [PAST]”
Return to the “SELF-DIAG [CURRENT]” CONSULT-II screen by
touching “BACK” key of CONSULT-II and select “SELF-DIAG
[PAST]” in SELECT DIAG MODE. Touch “ERASE” in “SELF-
DIAG [PAST]” mode.
NOTE:
If the memory of the malfunction in “SELF-DIAG [PAST]” is
not erased, the User mode will continue to show the system
malfunction by the operation of the warning lamp even if
the malfunction is repaired completely.
“TROUBLE DIAG RECORD”
The memory of “TROUBLE DIAG RECORD” cannot be erased.
Self-Diagnosis Function (Without CONSULT-II)EHS0016R
The reading of these results is accomplished using one of two modes — “User mode” and “Diagnosis
mode”.
After a malfunction is repaired, turn the ignition switch OFF for at least one second, then back ON. Diag-
nosis mode returns to the User mode. At that time, the self-diagnostic result is cleared.
HOW TO CHANGE SELF-DIAGNOSIS MODE
SRS7 01
SRS7 02
SHIA0183E
TROUBLE DIAGNOSIS
SRS-23
C
D
E
F
G
I
J
K
L
MA
B
SRS
Revision: October 20052005 QX56
7. Diagnostic code is displayed on "SELF-DIAG [CURRENT]".
If no malfunction is detected on "SELF-DIAG [CURRENT]" even
though malfunction is detected in "SRS Operation Check", refer to
SRS-31, "
DIAGNOSTIC PROCEDURE 4 (CONTINUED FROM
DIAGNOSTIC PROCEDURE 2)" , to diagnose the following cases:
Self-diagnostic result "SELF-DIAG [PAST]" (previously stored in
the memory) might not be erased after repair.
The SRS system malfunctions intermittently.
CONSULT-II Diagnostic Code Chart ("SELF-DIAG [CURRENT]")
WHIA0151E
SRS7 01
Diagnostic item ExplanationRepair order
Recheck SRS at each replacement
NO DTC IS DETECTEDWhen malfunction is
indicated by the “AIR
BAG” warning lamp in
User mode.
Low battery voltage (Less than
9V)Go to SRS-28, "DIAGNOSTIC PRO-
CEDURE 3" .
Self-diagnostic result “SELF-DIAG
[PAST]” (previously stored in the
memory) might not be erased
after repair.
Intermittent malfunction has been
detected in the past.
Go to SRS-31, "DIAGNOSTIC PRO-
CEDURE 4 (CONTINUED FROM
DIAGNOSTIC PROCEDURE 2)" .
Go to SRS-31, "DIAGNOSTIC PRO-
CEDURE 5" .
No malfunction is detected. —
DRIVER AIRBAG MODULE
[OPEN]
[B1049] or [B1054]
Driver air bag module circuit is open (including the spiral
cable).1. Visually check the wiring harness
connection.
2. Replace the harness if it has visible
damage.
3. Replace driver air bag module.
4. Replace the spiral cable.
5. Replace the air bag diagnosis sen-
sor unit.
6. Replace the related harness. DRIVER AIRBAG MODULE
[VB-SHORT]
[B1050] or [B1055]
Driver air bag module circuit is shorted to some power sup-
ply circuit (including the spiral cable).
DRIVER AIRBAG MODULE
[GND-SHORT]
[B1051] or [B1056]
Driver air bag module circuit is shorted to ground (including
the spiral cable).
DRIVER AIRBAG MODULE
[SHORT]
[B1052] or [B1057]
Driver air bag module circuits are shorted to each other.
SRS-32
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
6. Touch “SELF-DIAG [PAST]”.
7. If diagnostic codes are displayed on “SELF-DIAG [PAST]”, go to
step 10.
If no malfunction is detected on “SELF-DIAG [PAST]”, touch
“BACK” and go back to “SELECT DIAG MODE”.
8. Touch “TROUBLE DIAG RECORD”.
NOTE:
With “TROUBLE DIAG RECORD”, diagnosis results previ-
ously erased by a reset operation can be displayed.
9. Diagnostic code is displayed on “TROUBLE DIAG RECORD”.
10. Touch “PRINT”.
11. Compare diagnostic codes to SRS-33, "
CONSULT-II Diagnostic
Code Chart ("SELF-DIAG [PAST]" or "TROUBLE DIAG
RECORD")" .
12. Touch “BACK” key of CONSULT-II until “SELECT SYSTEM”
appears.
13. Turn ignition switch OFF, then turn off and disconnect CON-
SULT-II, and both battery cables.
BCIA0031E
WHIA0152E
SRS7 02
BCIA0031E
WHIA0153E
SRS-44
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
Trouble Diagnosis: “AIR BAG” Warning Lamp Does Not Turn OffEHS0016V
DIAGNOSTIC PROCEDURE 6
1. CHECK CONDITION OF AIR BAG MODULE
Inspect for any deployed air bag modules or seat belt pre-tensioners.
Are any air bag modules or seat belt pre-tensioners deployed?
Yes >> Refer to SRS-61, "COLLISION DIAGNOSIS" .
No >> GO TO 2.
2. CHECK THE AIR BAG FUSE
Check 10A fuse [No. 13, located in the fuse block (J/B)].
Refer to PG-4, "
POWER SUPPLY ROUTING CIRCUIT" .
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. CHECK AIR BAG FUSE AGAIN
Replace 10A fuse [No. 13, located in the fuse block (J/B)] and turn ignition switch ON.
Does the fuse blow again?
Yes >> Repair main harness.
No >> Inspection End.
4. CHECK AIR BAG DIAGNOSIS SENSOR UNIT
Connect CONSULT-II and touch “START”.
Is
“AIR BAG” displayed on CONSULT-II?
Yes >> GO TO 5.
No >> Visually inspect the air bag diagnosis sensor unit har-
ness connections. If the connections are OK, replace
the air bag diagnosis sensor unit. Refer to SRS-59,
"Removal and Installation" .
5. CHECK HARNESS CONNECTION
Check for loose connections between the combination meter and the air bag diagnosis sensor unit.
OK or NG
OK >> Replace air bag diagnosis sensor unit. Refer to SRS-59, "Removal and Installation" .
NG >> Properly connect the combination meter and air bag diagnosis sensor unit harness connectors. If
“AIR BAG” warning lamp still does not turn off, replace the wiring harness.
BCIA0030E
TF-18
ALL-MODE 4WD SYSTEM
Revision: October 20052005 QX56
LINE PRESSURE SWITCH
With the transfer system design, control of the oil pressure provides the transmission of drive torque to the
front wheels. The main pressure to control the oil pressure is referred to as the line pressure.
The line pressure switch determines whether or not adequate line pressure has built up under different
operating conditions.
The line pressure switch turns ON when line pressure is produced.
The line pressure switch senses line pressure abnormalities and turns the 4WD warning lamp ON.
CLUTCH PRESSURE SWITCH
The clutch pressure switch determines whether or not adequate clutch pressure has built up under differ-
ent operating conditions.
The clutch pressure switch turns ON when clutch pressure is produced.
The clutch pressure switch senses clutch pressure abnormalities and turns the 4WD warning lamp ON.
TRANSFER FLUID TEMPERATURE SENSOR
The transfer temperature sensor detects the transfer fluid temperature and sends a signal to the transfer con-
trol unit.
TRANSFER CONTROL UNIT
Transfer control unit controls transfer control device by input signals of each sensor and each switch.
Self-diagnosis can be done.
TRANSFER CONTROL DEVICE
The transfer control device changes the state of transfer assembly between 2WD, AUTO, 4H⇔4LO with the
2WD, AUTO, 4H and 4LO signals of 4WD shift switch.
NOTE:
To shift between 4H⇔4LO, stop the vehicle, depress the brake pedal and shift the transmission selector
to the "N" position. Depress and turn the 4WD shift switch. The shift switch will not shift to the desired
mode if the transmission is not in "N" or the vehicle is moving. The 4LO indicator lamp will be lit when the
4LO is engaged.
Actuator motor and actuator position switch are integrated.
4WD SHIFT SWITCH AND INDICATOR LAMP
4WD Shift Switch
The 4WD shift switch allows selection from 2WD, AUTO, 4H or 4LO.
4WD Shift Indicator Lamp
Displays driving conditions selected by 4WD shift switch with 2WD, AUTO and 4H indicators while engine
is running. (When 4WD warning lamp is turned on, all 4WD shift indicator lamps are turned off.)
Turns ON for approximately 1 second when ignition switch is turned ON, for purpose of lamp check.
4LO Indicator Lamp
Displays 4LO condition while engine is running. 4LO indicator lamp flashes if transfer gear does not shift
completely under 2WD, AUTO, 4H⇔4LO. (When 4WD warning lamp is turned on, 4LO indicator lamp is
turned off.)
Turns ON for approximately 1 second when ignition switch is turned ON, for purpose of lamp check.
TF-20
ALL-MODE 4WD SYSTEM
Revision: October 20052005 QX56
COMPONENTS FUNCTION
CAN CommunicationEDS002HC
SYSTEM DESCRIPTION
Refer to LAN-5, "CAN COMMUNICATION" .
Component parts Function
Transfer control unit Controls transfer control device and control valves.
Transfer control device Actuator motor and actuator position switch are integrated so as to switch driving types.
2-4WD shift solenoid valve Controls oil pressure and allows selection between 2WD and 4WD.
Clutch pressure solenoid valve Controls oil pressure and distributes torque (front and rear).
Line pressure switch Detects line pressure.
Clutch pressure switch Detects clutch pressure.
Transfer fluid temperature sen-
sorDetects transfer fluid temperature.
Wait detection switch Detects whether or not 4WD lock gear is locked.
Neutral-4LO switch Detects that transfer is under neutral-4LO condition (or shifting through neutral).
ATP switch Detects that transfer is under neutral condition.
4WD shift switch Allows selection from 2WD, AUTO, 4H or 4LO.
4WD warning lamp
Illuminates if malfunction is detected in electrical system of 4WD system.
There is 1 blink every 2 seconds if rotation difference of front wheels and rear wheels is large.
There is 2 blinks every 1 second if high transfer fluid temperature is detected.
ATP warning lampIndicates that A/T parking mechanism does not operate when A/T selector lever is in “P” position
and transfer is under neutral condition.
4WD shift indicator lamp Displays driving condition selected by 4WD shift switch.
4LO indicator lamp Displays 4LO condition.
ABS actuator and electric unit
(control unit)Transmits vehicle speed signal via CAN communication to transfer control unit.
TCMTransmits the following signals via CAN communication to transfer control unit.
Output shaft revolution signal
A/T position indicator signal (PNP switch signal)
ECMTransmits the following signals via CAN communication to transfer control unit.
Engine speed signal
Accelerator pedal position signal