ABS NISSAN PATROL 1998 Y61 / 5.G Brake System User Guide

REAR WHEEL SENSOR
G SENSOR
Always replace G sensor if bumped or dropped. Otherwise,
performance characteristics of G sensor will be changed,
which in turn changes ABS control performance characteris-
tics.
SBR188E
SBR190E
ANTI-LOCK BRAKE SYSTEM
Removal and Installation (Cont'd)BR-37

ABS ACTUATOR AND ELECTRIC UNIT
Removal
1. Disconnect battery cable.
2. Drain brake ¯uid. Refer to ``Changing Brake Fluid'', BR-3.
3. Remove mounting bracket ®xing bolts and nuts.
4. Disconnect connector, brake pipes and remove ®xing nuts.
Installation
CAUTION:
After installation, re®ll brake ¯uid. Then bleed air. Refer to
Bleeding Brake System'', BR-4.
1. Connect brake pipes temporarily.
2. Tighten ®xing bolts and nuts.
3. Tighten brake pipes.
4. Connect connector and battery cable.
SBR191E
ANTI-LOCK BRAKE SYSTEM
Removal and Installation (Cont'd)BR-38

How to Perform Trouble Diagnoses for Quick
and Accurate Repair
INTRODUCTION
The ABS system has an electronic control unit to control major
functions. The control unit accepts input signals from sensors and
instantly drives the actuators. It is essential that both kinds of sig-
nals are proper and stable. It is also important to check for conven-
tional problems: such as air leaks in booster lines, lack of brake
¯uid, or other problems with the brake system.
It is much more difficult to diagnose a problem that occurs intermit-
tently rather than continuously. Most intermittent problems are
caused by poor electric connections or faulty wiring. In this case,
careful checking of suspicious circuits may help prevent the
replacement of good parts.
A visual check only may not ®nd the cause of the problems, so a
road test should be performed.
Before undertaking actual checks, take a few minutes to talk with
a customer who approaches with a ABS complaint. The customer
is a very good source of information on such problems; especially
intermittent ones. Through the talks with the customer, ®nd out what
symptoms are present and under what conditions they occur.
Start your diagnosis by looking for ``conventional'' problems ®rst.
This is one of the best ways to troubleshoot brake problems on an
ABS controlled vehicle.
SEF233G
SEF234G
TROUBLE DIAGNOSES
BR-39

Wiring Diagram Ð ABS Ð
TBR099
TROUBLE DIAGNOSES
BR-43

TBR100
TROUBLE DIAGNOSES
Wiring Diagram Ð ABS Ð (Cont'd)BR-44

TBR101
TROUBLE DIAGNOSES
Wiring Diagram Ð ABS Ð (Cont'd)BR-45

TBR102
TROUBLE DIAGNOSES
Wiring Diagram Ð ABS Ð (Cont'd)BR-46

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