1998 NISSAN PICK-UP sensor

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 signals are proper and stable. It is also important to check for
conventional problems: such as air leaks in booster lines, lack of
brake fluid, or other problems with the brake system.
It is much more difficult to diagnose a problem that occurs inter-
mittently 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 find 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 cus-
tomer is a very good source of information on such problems;
especially intermittent ones. Through the talks with the customer,
find out what symptoms are present and under what conditions
they occur.
Start your diagnosis by looking for ``conventional'' problems first.
This is one of the best ways to troubleshoot brake problems on
an ABS controlled vehicle.
SEF233G
SEF234G
TROUBLE DIAGNOSES
BR-38

MALFUNCTION CODE/SYMPTOM CHART
Code No.
(No. of warning lamp flashes)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
25.3 Front left sensor (open-circuit) 1
26.3 Front left sensor (short-circuit) 1
21.3 Front right sensor (open-circuit) 1
22.3 Front right sensor (short-circuit) 1
35.1,.3 Rear sensor (open-circuit) 1
36.1,.3 Rear sensor (short-circuit) 1
31.2,.3 Rear right sensor (open-circuit) 1
32.2,.3 Rear right sensor (short-circuit) 1
35.2,.3 Rear left sensor (open-circuit) 1
36.2,.3 Rear left sensor (short-circuit) 1
18.3 Sensor rotor 1
17.2 G sensor and circuit 5
61.5 Actuator motor or motor relay 3
63 Solenoid valve relay 2
57.4 Power supply (Low voltage) 4
71 Control unit 6
Warning lamp stays on when igni-
tion switch is turned onControl unit power supply circuit
Warning lamp bulb circuit
Control unit or control unit connector
Solenoid valve relay stuck
Power supply for solenoid valve relay coil13
Warning lamp does not come on
when ignition switch is turned onFuse, warning lamp bulb or warning lamp circuit
Control unit12
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: 2WD model only
.2: 4WD model only
.3: 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 specified in ``SELF-DIAGNOSIS PROCEDURE'', BR-53. Check to ensure that the ABS
warning lamp goes out while the vehicle is being driven.
.4: 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.
.5: 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-55

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-53.)
ITEMSELF-DIAGNOSTIC
RESULTSDATA MONITOR ACTIVE TEST
Front right wheel sensor X X Ð
Front left wheel sensor X X Ð
Rear wheel sensor.1X X Ð
Rear right wheel sensor.2X X Ð
Rear left wheel sensor.2X X Ð
G switch (G sensor).2XXX
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
.1: 2WD model only
.2: 4WD model only
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-56

SELF-DIAGNOSTIC RESULTS MODE
Diagnostic item Diagnostic item is detected when ...Diagnostic
procedure
FR RH SENSOR.1
[OPEN]
lCircuit for front right wheel sensor is open.
(An abnormally high input voltage is entered.)1
FR LH SENSOR.1
[OPEN]
lCircuit for front left wheel sensor is open.
(An abnormally high input voltage is entered.)1
RR SENSOR.1,.2
[OPEN]
lCircuit for rear sensor is open.
(An abnormal high input voltage is entered.)1
RR RH SENSOR.1,.3
[OPEN]
lCircuit for rear right sensor is open.
(An abnormally high input voltage is entered.)1
RR LH SENSOR.1,.3
[OPEN]
lCircuit for rear left sensor is open.
(An abnormally high input voltage is entered.)1
FR RH SENSOR.1
[SHORT]
lCircuit for front right wheel sensor is shorted.
(An abnormally low input voltage is entered.)1
FR LH SENSOR.1
[SHORT]
lCircuit for front left wheel sensor is shorted.
(An abnormally low input voltage is entered.)1
RR SENSOR.1,.2
[SHORT]
lCircuit for rear sensor is shorted.
(An abnormal low input voltage is entered.)1
RR RH SENSOR.1,.3
[SHORT]
lCircuit for rear right sensor is shorted.
(An abnormally low input voltage is entered.)1
RR LH SENSOR.1,.3
[SHORT]
lCircuit for rear left sensor is shorted.
(An abnormally low input voltage is entered.)1
ABS SENSOR.1
[ABNORMAL SIGNAL]
lTeeth damage on sensor rotor or improper installation of wheel sensor.
(Abnormal wheel sensor signal is entered.)1
FR RH IN ABS SOL
[OPEN]
lCircuit for front right inlet solenoid valve is open.
(An abnormally low output voltage is entered.)2
FR LH IN ABS SOL
[OPEN]
lCircuit for front left inlet solenoid valve is open.
(An abnormally low output voltage is entered.)2
RR IN ABS SOL
[OPEN]
lCircuit for rear inlet solenoid valve is open.
(An abnormally low output voltage is entered.)2
FR RH IN ABS SOL
[SHORT]
lCircuit for front right inlet solenoid valve is shorted.
(An abnormally high output voltage is entered.)2
FR LH IN ABS SOL
[SHORT]
lCircuit for front left inlet solenoid valve is shorted.
(An abnormally high output voltage is entered.)2
RR IN ABS SOL
[SHORT]
lCircuit for rear inlet solenoid valve is shorted.
(An abnormally high output voltage is entered.)2
FR RH OUT ABS SOL
[OPEN]
lCircuit for front right outlet solenoid valve is open.
(An abnormally low output voltage is entered.)2
FR LH OUT ABS SOL
[OPEN]
lCircuit for front left outlet solenoid valve is open.
(An abnormally low output voltage is entered.)2
RR OUT ABS SOL
[OPEN]
lCircuit for rear outlet solenoid valve is open.
(An abnormally low output voltage is entered.)2
FR RH OUT ABS SOL
[SHORT]
lCircuit for front right outlet solenoid valve is shorted.
(An abnormally high output voltage is entered.)2
FR LH OUT ABS SOL
[SHORT]
lCircuit for front left outlet solenoid valve is shorted.
(An abnormally high output voltage is entered.)2
RR OUT ABS SOL
[SHORT]
lCircuit for rear outlet solenoid valve is shorted.
(An abnormally high output voltage is entered.)2
ABS ACTUATOR RELAY
[ABNORMAL]
lActuator solenoid valve relay is ON, even if control unit sends off signal.lActuator solenoid valve relay is OFF, even if control unit sends on signal.2
ABS MOTOR RELAY
[ABNORMAL]
lCircuit for ABS motor relay is open or shorted.lCircuit for actuator motor is open or shorted.lActuator motor relay is stuck.3
BATTERY VOLT
[VB-LOW]
lPower source voltage supplied to ABS control unit is abnormally low. 4
CONTROL UNIT
lFunction of calculation in ABS control unit has failed. 6
G-SENSOR.3
[ABNORMAL]
lG sensor circuit is open or shorted. 5
.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 warn-
ing 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 specified in ``SELF-DIAGNOSIS PROCEDURE'', BR-53. Check to ensure that the ABS
warning lamp goes out while the vehicle is being driven.
.2: 2WD model only
.3: 4WD model only
TROUBLE DIAGNOSES
CONSULT Inspection Procedure (Cont'd)
BR-58

DATA MONITOR MODE
MONITOR ITEM CONDITION SPECIFICATION
FR RH SENSOR
FR LH SENSOR
RR SENSOR.1
RR RH SENSOR.2
RR LH SENSOR.2Drive vehicle.
(Each wheel is rotating.)Wheel speed signal
(Almost the same speed as speedometer.)
STOP LAMP SW Brake is depressed.Depress the pedal: ON
Release the pedal: OFF
G-SWITCH.2Vehicle is driven.
Vehicle is stopped.
Brake is applied.During sudden braking while driving on high  roads (asphalt
roads, etc.): OFF
While vehicle is stopped or during constant-speed driving: ON
FR RH IN SOL
FR RH OUT SOL
FR LH IN SOL
FR LH OUT SOL
RR IN SOL
RR OUT SOL1. Drive vehicle at speeds over
30 km/h (19 MPH) for at
least one minute.
2. Engine is running.Operating conditions for each solenoid valve are indicated.
ABS is not operating: OFF
MOTOR RELAYABS is not operating: OFF
ABS is operating: ON
ACTUATOR RELAY
Ignition switch is ON or
engine is running.Ignition switch ON (Engine stops): OFF
Engine running: ON
WARNING LAMPABS warning lamp is turned on: ON
ABS warning lamp is turned off: OFF
BATTERY VOLT Power supply voltage for control unit
.1: 2WD model only
.2: 4WD model only
ACTIVE TEST MODE
TEST ITEM CONDITION JUDGEMENT
FR RH SOLENOID
FR LH SOLENOID
REAR SOLENOID
Engine is running.Brake fluid pressure control operation
IN SOL OUT SOL
UP (Increase):
KEEP (Hold):
DOWN (Decrease):OFF
ON
ONOFF
OFF
ON
ABS MOTORABS actuator motor
ON: Motor runs (ABS motor relay ON)
OFF: Motor stops (ABS motor relay OFF)
G SWITCH.Ignition switch is ON.G SWITCH (G SENSOR),
ON: Set G SWITCH MONITOR ``ON''
(G switch circuit is closed.)
OFF: Set G SWITCH MONITOR ``OFF''
(G switch circuit is open.)
.: 4WD model only
Note: Active test will automatically stop ten seconds after the test starts. (LIMIT SIGNAL monitor
shows ON.)
TROUBLE DIAGNOSES
CONSULT Inspection Procedure (Cont'd)
BR-61

Diagnostic Procedure 1
(Wheel sensor or rotor)
Malfunction code No. 21, 22, 25, 26, 31, 32, 35, 36 or 18
INSPECTION START
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1. Disconnect connectors from ABS
actuator and electric unit and wheel
sensor of malfunction code No. Check
terminals for damage or loose connec-
tions. Then reconnect connectors.
2. Carry out self-diagnosis again.
Does warning lamp activate again?
Yes
cNo
Inspection end
CHECK WHEEL SENSOR ELECTRI-
CAL.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1. Disconnect ABS actuator and electric
unit connector.
2. Check resistance between ABS actua-
tor and electric unit connector
E4
(body side) terminals.
Code No. 21 or 22 (Front RH wheel)
Terminals
V4andV5
Code No. 25 or 26 (Front LH wheel)
Terminals
V6andV7
Code No. 31 or 32 (4WD Rear RH
wheel)
Terminals
V8andV9
Code No. 35 or 36 (2WD Rear, 4WD
Rear LH wheel)
Terminals
V8andV9(2WD Rear
wheel)
Terminals
V1andV2(4WD Rear LH
wheel)
Resistance:
Front 1.44 - 1.76 kW
Rear (2WD) 1.22 - 1.48 kW
Rear (4WD) 1.44 - 1.76 kW
NG
cOKVA(Go to next page.)
CHECK WHEEL SENSOR.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Check each sensor for resistance.
Resistance: Front 1.44 - 1.76 kW
Rear (2WD) 1.22 - 1.48 kW
Rear (4WD) 1.44 - 1.76 kW
NG
cOK
Check the following.
lHarness connectorsE4,E31,E15,BR1,BR5,C5
lHarness for open or
short between wheel
sensor connectors and
ABS actuator and elec-
tric unit
If NG, repair harness or
connectors.
REPLACE.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Replace wheel sensor.
SBR046EA
SBR047EB
SBR048ED
SBR049EA
.
.
.
TROUBLE DIAGNOSES FOR SELF-DIAGNOSTIC ITEMS
BR-63

VA
Note
CHECK TIRE.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Check for inflation pressure, wear and
size of each tire.
OK
cNGNote
Adjust tire pressure or
replace tire(s).
Note
CHECK WHEEL BEARING.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Check wheel bearing axial end play.
OK
Note
CHECK SENSOR ROTOR.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Check sensor rotor for teeth damage.
OK
cNGNote
Replace sensor rotor.
CHECK HARNESS CONNECTOR.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Check ABS actuator and electric unit pin
terminals for damage or the connection of
ABS actuator and electric unit harness
connector. Reconnect ABS actuator and
electric unit harness connector. Then
retest.
Note: Wheel position should be distinguished by code num-
bers except code No. 18 (sensor rotor).
.
.
.
.
TROUBLE DIAGNOSES FOR SELF-DIAGNOSTIC ITEMS
Diagnostic Procedure 1
(Wheel sensor or rotor) (Cont'd)
BR-64

Diagnostic Procedure 5 (G sensor)
Malfunction code No. 17
CHECK G SENSOR POWER SUPPLY
CIRCUIT.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Check 10A fuse
14. For fuse layout, refer
to POWER SUPPLY ROUTING in EL sec-
tion.
OK
cNG
Replace fuse.
CHECK CONNECTOR.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1. Disconnect ABS actuator and electric
unit connector. Check terminals for
damage or loose connection. Then
reconnect connector.
2. Carry out self-diagnosis again.
Does warning lamp activate again?
Yes
cNo
Inspection end
CHECK G SENSOR.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Refer to G SENSOR in Electrical Compo-
nents Inspection, BR-71.
OK
cNG
Replace G sensor.
CHECK G SENSOR POWER SUPPLY
CIRCUIT.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1. Disconnect G sensor connector.
2. Check voltage between G sensor con-
nector
M101,M102(body side) terminal
V2,V15and ground.
Battery voltage should exist.
OK
cNG
Check the following.
lHarness connectorsM101,M102,E4
lHarness for open or short
between G sensor and
ABS actuator and electric
unit
If NG, repair harness or
connectors.
CHECK G SENSOR GROUND.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1. Disconnect ABS actuator and electric
unit connector and G sensor connec-
tors.
2. Check continuity between ABS actuator
and electric unit connector
E4(body
side) terminals
V10,V20and G sensor
connectors
M101,M102(body side) ter-
minals
V10,V20.
Continuity should exist.
OK
cNG
Check the following.
lHarness connectorsM101,M102,E4
lHarness for open or short
between G sensor and
ABS actuator and electric
unit
If NG, repair harness or
connectors.
CHECK HARNESS CONNECTOR.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Check ABS actuator and electric unit pin
terminals for damage or the connection of
ABS actuator and electric unit harness
connector. Reconnect ABS actuator and
electric unit harness connector. Then
retest.
SBR059E
SBR060E
SBR061E
.
.
.
.
.
TROUBLE DIAGNOSES FOR SELF-DIAGNOSTIC ITEMS
BR-70