1998 NISSAN PATROL Abs lamp

Ground Circuit Check ................................................56
TROUBLE DIAGNOSES FOR SELF-DIAGNOSTIC
ITEMS ........................................................................\
.....57
Diagnostic Procedure 1 (Wheel sensor or rotor) ......57
Diagnostic Procedure 2 (ABS actuator solenoid
valve and solenoid valve relay) .................................59
Diagnostic Procedure 3 (Motor relay or motor).........61
Diagnostic Procedure 4 (Low voltage) ......................63
Diagnostic Procedure 5 (G sensor) ...........................64
Diagnostic Procedure 6 (Control unit) .......................65
TROUBLE DIAGNOSES FOR SYMPTOMS .................66
Diagnostic Procedure 7 (ABS works frequently.) ......66
Diagnostic Procedure 8 (Unexpected pedal
action) ........................................................................\
67 Diagnostic Procedure 9 (Long stopping distance) ....67
Diagnostic Procedure 10 (ABS does not work.) .......68
Diagnostic Procedure 11 (Pedal vibration and
noise) ........................................................................\
.68
Diagnostic Procedure 12 (Warning lamp does
not come on when ignition switch is turned ON.) .....69
Diagnostic Procedure 13 (Warning lamp stays on
when ignition switch is turned ON.)...........................71
SERVICE DATA AND SPECIFICATIONS (SDS) ..........72
General Speci®cations ...............................................72
Inspection and Adjustment ........................................73
When you read wiring diagrams:
+ Read GI section, ``HOW TO READ WIRING DIAGRAMS''.
+ See EL section, ``POWER SUPPLY ROUTING'' for power distribution circuit.
When you perform trouble diagnoses, read GI section, ``HOW TO FOLLOW FLOW CHART
IN TROUBLE DIAGNOSES'' and ``HOW TO PERFORM EFFICIENT DIAGNOSIS FOR AN
ELECTRICAL INCIDENT''.

Purpose
The Anti-Lock Brake System (ABS) consists of electronic and hydraulic components. It allows for control of
braking force so locking of the wheels can be avoided.
The ABS:
1) Improves proper tracking performance through steering wheel operation.
2) Eases obstacle avoidance through steering wheel operation.
3) Improves vehicle stability.
Operation
+When the vehicle speed is less than 10 km/h (6 MPH) this system does not work.
+ The Anti-Lock Brake System (ABS) has a self-test function. The system turns on the ABS warning lamp
for 1 second each time the ignition switch is turned ``ON''. After the engine is started, the ABS warning
lamp turns off. The system performs a test the ®rst time the vehicle reaches 6 km/h (4 MPH). A mechani-
cal noise may be heard as the ABS performs this self-test. This is a normal part of the self-test feature. If
a malfunction is found during this check, the ABS warning lamp will stay on.
+ While driving, a mechanical noise may be heard during ABS operation. This is a normal condition.
+ While DIFF-LOCK is on, the anti-lock brake warning light ¯ashes. This indicates that anti-lock may not be
fully operated. (ABS only)
ABS Hydraulic Circuit
j1Inlet solenoid valve
j
2Outlet solenoid valve
j
3Reservoir j
4Pump
j
5Motor
j
6Inlet valve j
7Outlet valve
j
8Bypass check valve
j
9Damper
SBR211E
ANTI-LOCK BRAKE SYSTEM
BR-33

System Components
System Description
WHEEL SENSOR
The sensor unit consists of a gear-shaped sensor rotor and a sen-
sor element. The element contains a bar magnet around which a
coil is wound. The sensor is installed on the back of the brake rotor.
As the wheel rotates, the sensor generates a sine-wave pattern.
The frequency and voltage increase(s) as the rotating speed
increases.
CONTROL UNIT (built in ABS actuator and electric unit)
The control unit computes the wheel rotating speed by the signal
current sent from the sensor. Then it supplies a DC current to the
actuator solenoid valve. It also controls ON-OFF operation of the
valve relay and motor relay. If any electrical malfunction should be
detected in the system, the control unit causes the warning lamp
to light up. In this condition, the ABS will be deactivated by the
control unit, and the vehicle's brake system reverts to normal
operation. (For control unit layout, refer to ABS ACTUATOR AND
ELECTRIC UNIT, BR-34.)
SBR185E
SBR186E
ANTI-LOCK BRAKE SYSTEM
BR-34

Self-diagnosis
FUNCTION
+When a problem occurs in the ABS, the warning lamp on the
instrument panel comes on. To start the self-diagnostic results
mode, ground the self-diagnostic (check) terminal located on
``Data Link Connector for CONSULT''. The location of the mal-
function is indicated by the warning lamp ¯ashing.
+ While DIFF-LOCK is on, anti-lock warning light ¯ashes.
SELF-DIAGNOSIS PROCEDURE
Turn off DIFF-LOCK switch.
Drive vehicle over 30 km/h (19 MPH) for
at least one minute.
Turn ignition switch ``OFF''.
Ground terminal ``4'' of ``Data link con-
nector for CONSULT'' with a suitable har-
ness.
Turn ignition switch ``ON'' while ground-
ing terminal ``4''.
Do not depress brake pedal.
After 3.0 seconds, the warning lamp
starts ¯ashing to indicate the malfunction
code No. (See NOTE.)
Verify the location of the malfunction with
the malfunction code chart. Refer to
BR-48. Then make the necessary repairs
following the diagnostic procedures.
After the malfunctions are repaired, erase
the malfunction codes stored in the con-
trol unit. Refer to BR-47.
Rerun the self-diagnostic results mode to
verify that the malfunction codes have
been erased.
Disconnect the check terminal from the
ground. The self-diagnostic results mode
is now complete.NOTE: The indication terminates
after ®ve minutes.
However, when the ignition
switch is turned from
``OFF'' to ``ON'', the indica-
tion starts ¯ashing again.
j
A
SBR193E
SBR186E
SBR194E
.
.
.
.
.
.
.
.
.
TROUBLE DIAGNOSES
BR-47

jA
Check warning lamp for deactivation after
driving vehicle over 30 km/h (19 MPH)
for at least one minute.
After making certain that warning lamp
does not come on, test the ABS in a safe
area to verify that it functions properly.
HOW TO READ SELF-DIAGNOSTIC RESULTS (Malfunction codes)
+Determine the code No. by counting the number of times the warning lamp ¯ashes on and off.
+ When several malfunctions occur at one time, up to three code numbers can be stored; the latest mal-
function will be indicated ®rst.
+ The indication begins with the start code 12. After that a maximum of three code numbers appear in the
order of the latest one ®rst. The indication then returns to the start code 12 to repeat (the indication will
stay on for ®ve minutes at the most).
+ The malfunction code chart is given on the next page.
HOW TO ERASE SELF-DIAGNOSTIC RESULTS
(Malfunction codes)
1. Disconnect the check terminal from ground (ABS warning lamp
will stay lit).
2. Within 12.5 seconds, ground the check terminal 3 times. Each terminal ground must last more than 1 second. The ABS warn-
ing lamp goes out after the erase operation has been com-
pleted.
3. Perform self-diagnosis again. Refer to BR-47. Only the start- code should appear, no malfunction codes.
SBR457D
ABR256
.
.
TROUBLE DIAGNOSES
Self-diagnosis (Cont'd)
BR-48

MALFUNCTION CODE/SYMPTOM CHART
Code No.
(No. of warning lamp ¯ashes) Malfunctioning part Diagnostic procedure
45 Actuator front left outlet solenoid valve 2
46 Actuator front left inlet solenoid valve 2
41 Actuator front right outlet solenoid valve 2
42 Actuator front right inlet solenoid valve 2
55 Actuator rear outlet solenoid valve 2
56 Actuator rear inlet solenoid valve 2
25 .1 Front left sensor (open-circuit) 1
26 .1 Front left sensor (short-circuit) 1
21 .1 Front right sensor (open-circuit) 1
22 .1 Front right sensor (short-circuit) 1
31 .1 Rear right sensor (open-circuit) 1
32 .1 Rear right sensor (short-circuit) 1
35 .1 Rear left sensor (open-circuit) 1
36 .1 Rear left sensor (short-circuit) 1
18 .1 Sensor rotor 1
17 G sensor and circuit 5
61 .3 Actuator motor or motor relay 3
63 Solenoid valve relay 2
57 .2 Power supply (Low voltage) 4
71 Control unit 6
Warning lamp stays on when igni-
tion switch is turned on Control unit power supply circuit
Warning lamp bulb circuit
Control unit or control unit connector
Solenoid valve relay stuck
Power supply for solenoid valve relay coil
13
Warning lamp does not come on
when ignition switch is turned on Fuse, warning lamp bulb or warning lamp circuit
Control unit
12
Pedal vibration and noise Ð 11
Long stopping distance Ð 9
Unexpected pedal action Ð 8
ABS does not work Ð 10
ABS works frequently Ð 7
. 1: If one or more wheels spin on a rough or slippery road for 40 seconds or more, the ABS warning lamp will illuminate. This does
not indicate a malfunction. Only in the case of the short-circuit (Code Nos. 26, 22, 32 and 36), after repair the ABS warning lamp
also illuminates when the ignition switch is turned ``ON''. In this case, drive the vehicle at speeds greater than 30 km/h (19 MPH)
for approximately 1 minute as speci®ed in ``SELF-DIAGNOSIS PROCEDURE'', BR-47. Check to ensure that the ABS warning
lamp goes out while the vehicle is being driven.
. 2: The trouble code ``57'', which refers to a low power supply voltage, does not indicate that the ABS control unit is malfunctioning.
Do not replace the ABS control unit with a new one.
. 3: The trouble code ``61'' can sometimes appear when the ABS motor is not properly grounded. If it appears, be sure to check the
condition of the ABS motor ground circuit connection.
TROUBLE DIAGNOSES
Self-diagnosis (Cont'd)
BR-49

CONSULT
CONSULT APPLICATION TO ABS
EE960 program card is not applicable to ABS. Use on board diagnostic system with ABS warning lamp until
the next program card will be introduced. (Refer to ``Self-diagnosis'', BR-47.)
ITEMSELF-DIAGNOSTIC
RESULTS DATA MONITOR ACTIVE TEST
Front right wheel sensor X X Ð
Front left wheel sensor X X Ð
Rear right wheel sensor X X Ð
Rear left wheel sensor X X Ð
G switch (G sensor) X X X
Stop lamp switch Ð X Ð
Front right inlet solenoid valve X X X
Front right outlet solenoid valve X X X
Front left inlet solenoid valve X X X
Front left outlet solenoid valve X X X
Rear inlet solenoid valve X X X
Rear outlet solenoid valve X X X
Actuator solenoid valve relay X X Ð
Actuator motor relay
(ABS MOTOR is shown on the Data Monitor
screen.) XXX
ABS warning lamp Ð X Ð
Battery voltage X X Ð
X: Applicable
Ð: Not applicable
ECU (ABS control unit) part number mode
Ignore the ECU part number displayed in the ECU PART NUMBER MODE. Refer to parts catalog to order
the ECU.
TROUBLE DIAGNOSES
BR-50

CONSULT Inspection Procedure
SELF-DIAGNOSIS PROCEDURE
1) Turn ignition switch OFF.
2) Connect CONSULT to Data Link Con- nector for CONSULT.
1) Start engine.
2) Drive vehicle over 30 km/h (19 MPH) for at least one minute.
1) Stop vehicle with engine runningand touch ``START'' on CONSULT
screen.
2) Touch ``ABS''.
3) Touch ``SELF-DIAG RESULTS''.
+ The screen shows the detected mal-
function and how many times the igni-
tion switch has been turned since the
malfunction.
Make the necessary repairs following the
diagnostic procedures.
After the malfunctions are repaired, erase
the self-diagnostic results stored in the
control unit by touching ``ERASE''.
Check warning lamp for deactivation after
driving vehicle over 30 km/h (19 MPH) for
at least one minute.
Test the ABS in a safe area to verify that it
functions properly.
Note: ``SELF-DIAG RESULTS'' screen shows the detected malfunction and how many times the ignition switch has been turned since the mal-
function.
SBR195E
SBR455D
SBR080E
SST412B
SBR950C
.
.
.
.
.
.
TROUBLE DIAGNOSES
BR-51